text
stringlengths
226
34.5k
java script html element scrape using a scrapy on phython 2.7.11 i get like these Question: [root@Imx8 craigslist_sample]# scrapy crawl spider /root/Python-2.7.11/craigslist_sample/craigslist_sample/spiders/test.py:1: ScrapyDeprecationWarning: Module `scrapy.spider` is deprecated, use `scrapy.spiders` instead from scrapy.spider import BaseSpider /root/Python-2.7.11/craigslist_sample/craigslist_sample/spiders/test.py:6: ScrapyDeprecationWarning: craigslist_sample.spiders.test.MySpider inherits from deprecated class scrapy.spiders.BaseSpider, please inherit from scrapy.spiders.Spider. (warning only on first subclass, there may be others) class MySpider(BaseSpider): 2016-10-18 18:23:30 [scrapy] INFO: Scrapy 1.2.0 started (bot: craigslist_sample) 2016-10-18 18:23:30 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'craigslist_sample.spiders', 'SPIDER_MODULES': ['craigslist_sample.spiders'], 'ROBOTSTXT_OBEY': True, 'BOT_NAME': 'craigslist_sample'} Traceback (most recent call last): File "/usr/local/bin/scrapy", line 11, in <module> sys.exit(execute()) File "/usr/local/lib/python2.7/site-packages/scrapy/cmdline.py", line 142, in execute _run_print_help(parser, _run_command, cmd, args, opts) File "/usr/local/lib/python2.7/site-packages/scrapy/cmdline.py", line 88, in _run_print_help func(*a, **kw) File "/usr/local/lib/python2.7/site-packages/scrapy/cmdline.py", line 149, in _run_command cmd.run(args, opts) File "/usr/local/lib/python2.7/site-packages/scrapy/commands/crawl.py", line 57, in run self.crawler_process.crawl(spname, **opts.spargs) File "/usr/local/lib/python2.7/site-packages/scrapy/crawler.py", line 162, in crawl crawler = self.create_crawler(crawler_or_spidercls) File "/usr/local/lib/python2.7/site-packages/scrapy/crawler.py", line 190, in create_crawler return self._create_crawler(crawler_or_spidercls) File "/usr/local/lib/python2.7/site-packages/scrapy/crawler.py", line 194, in _create_crawler spidercls = self.spider_loader.load(spidercls) File "/usr/local/lib/python2.7/site-packages/scrapy/spiderloader.py", line 43, in load raise KeyError("Spider not found: {}".format(spider_name)) KeyError: 'Spider not found: spider' Answer: your should set name='spider' in craigslist_sample/craigslist_sample/spiders/test.py class MySpider(Spider): name = 'spider' def parse(self,response): #....
Django AppsNotLoaded Question: I'm trying to make a python script to put some things in my database; from django.conf import settings settings.configure() import django.db from models import Hero #Does not work..? heroes = [name for name in open('hero_names.txt').readlines()] names_in_db = [hero.hero_name for hero in Hero.objects.all()] #ALready existing heroes for heroname in heroes: if heroname not in names_in_db: h = Hero(hero_name=heroname, portraid_link='/static/heroes/'+heroname) h.save() The import throws the following Traceback (most recent call last): File "heroes_to_db.py", line 4, in <module> from models import Hero File "C:\Users\toft_\Desktop\d2-patchnotes-master\dota2notes\patch\models.py", line 5, in <module> class Hero(models.Model): File "C:\Python27\lib\site-packages\django\db\models\base.py", line 105, in __new__ app_config = apps.get_containing_app_config(module) File "C:\Python27\lib\site-packages\django\apps\registry.py", line 237, in get_containing_app_config self.check_apps_ready() File "C:\Python27\lib\site-packages\django\apps\registry.py", line 124, in check_apps_ready raise AppRegistryNotReady("Apps aren't loaded yet.") django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet. I know I can do `python manage.py --shell` and write the code for hand but to be honest, I dont want to. What am I missing ? Answer: Django must configure all installed applications before you can use any models. To do this you must call `django.setup()` import django django.setup() [From the documentation:](https://docs.djangoproject.com/en/1.10/ref/applications/#how- applications-are-loaded) > This function is called automatically: > > * When running an HTTP server via Django’s WSGI support. > * When invoking a management command. > > > It must be called explicitly in other cases, for instance in plain Python > scripts.
large data transformation in python Question: I have a large data set (ten 12gb csv files) that have 25 columns and would want to transform it to a dataset with 6 columns. the first 3 columns remains the same whereas the 4th one would be the variable names and the rest contains data. Below is my input: #RIC Date[L] Time[L] Type L1-BidPrice L1-BidSize L1-AskPrice L1-AskSize L2-BidPrice L2-BidSize L2-AskPrice L2-AskSize L3-BidPrice L3-BidSize L3-AskPrice L3-AskSize L4-BidPrice L4-BidSize L4-AskPrice L4-AskSize L5-BidPrice L5-BidSize L5-AskPrice L5-AskSize HOU.ALP 20150901 30:10.8 Market Depth 5.29 50000 5.3 32000 5.28 50000 5.31 50000 5.27 50000 5.32 50000 5.26 50000 5.33 50000 5.34 50000 HOU.ALP 20150901 30:10.8 Market Depth 5.29 50000 5.3 44000 5.28 50000 5.31 50000 5.27 50000 5.32 50000 5.26 50000 5.33 50000 5.34 50000 HOU.ALP 20150901 30:12.1 Market Depth 5.29 50000 5.3 32000 5.28 50000 5.31 50000 5.27 50000 5.32 50000 5.26 50000 5.33 50000 5.34 50000 HOU.ALP 20150901 30:12.1 Market Depth 5.29 50000 5.3 38000 5.28 50000 5.31 50000 5.27 50000 5.32 50000 5.26 50000 5.33 50000 5.34 50000 and I would transform it to: #RIC Date[L] Time[L] level Bid_price bid_volume Ask_price Ask_volume HOU.ALP 20150901 30:10.8 L1 5.29 50000 5.3 50000 HOU.ALP 20150901 30:10.8 L2 5.28 50000 5.31 50000 HOU.ALP 20150901 30:12.1 L3 5.27 50000 5.32 50000 HOU.ALP 20150901 30:12.1 L4 5.26 50000 5.33 50000 HOU.ALP 20150901 30:12.1 L5 HOU.ALP 20150901 30:12.1 L1 5.29 50000 5.3 50000 HOU.ALP 20150901 30:12.1 L2 5.28 44000 5.31 50000 HOU.ALP 20150901 30:12.1 L3 5.27 48000 5.32 50000 HOU.ALP 20150901 30:12.1 L4 5.26 50000 5.33 50000 Here is my attempt with the coding. I think I would have to use dictionary to write to a csv file def depth_data_transformation(input_file_list, output_file): for file in input_file_list: file_to_open = '%s.csv' %file with open(file_to_open) as f, open(output_file, "w") as out: next(f) # skip header cols = ["#RIC", "Date[L]", "Time[L]", "level", "Bid_price", "bid_volume", "Ask_price", "Ask_volume"] wr = csv.writer(out) wr.writerow(cols) for row in csv.reader(f): # get all but first three cols it = row[4:] # zip_longest(*[iter(it)] * 4, fillvalue="") -> group into 4's, add empty string for missing values for ind, t in enumerate(izip_longest(*[iter(it)] * 4, fillvalue=""), 1): # first 3 cols, level and group all in one row/list. wr.writerow(row[:3]+ ["l{}".format(ind)] + list(t)) Answer: You need to group the levels, i.e `L1-BidPrice L1-BidSize L1-AskPrice L1-AskSize` and write each to a new row : import csv from itertools import zip_longest # izip_longest python2 with open("infile.csv") as f, open("out.csv", "w") as out: next(f) # skip header cols = ["#RIC", "Date[L]", "Time[L]", "level", "Bid_price", "bid_volume", "Ask_price", "Ask_volume"] wr = csv.writer(out) wr.writerow(cols) for row in csv.reader(f): # get all but first three cols. it = row[4:] # zip_longest(*[iter(it)] * 4, fillvalue="") -> group into 4's, add empty string for missing values for ind, t in enumerate(zip_longest(*[iter(it)] * 4, fillvalue=""), 1): # first 3 cols, level and group all in one row/list. wr.writerow(row[:3]+ ["l{}".format(ind)] + list(t)) Which would give you: #RIC,Date[L],Time[L],level,Bid_price,bid_volume,Ask_price,Ask_volume HOU.ALP,20150901,30:10.8,l1,5.29,50000,5.3,32000 HOU.ALP,20150901,30:10.8,l2,5.28,50000,5.31,50000 HOU.ALP,20150901,30:10.8,l3,5.27,50000,5.32,50000 HOU.ALP,20150901,30:10.8,l4,5.26,50000,5.33,50000 HOU.ALP,20150901,30:10.8,l5,5.34,50000,, HOU.ALP,20150901,30:10.8,l1,5.29,50000,5.3,44000 HOU.ALP,20150901,30:10.8,l2,5.28,50000,5.31,50000 HOU.ALP,20150901,30:10.8,l3,5.27,50000,5.32,50000 HOU.ALP,20150901,30:10.8,l4,5.26,50000,5.33,50000 HOU.ALP,20150901,30:10.8,l5,5.34,50000,, HOU.ALP,20150901,30:12.1,l1,5.29,50000,5.3,32000 HOU.ALP,20150901,30:12.1,l2,5.28,50000,5.31,50000 HOU.ALP,20150901,30:12.1,l3,5.27,50000,5.32,50000 HOU.ALP,20150901,30:12.1,l4,5.26,50000,5.33,50000 HOU.ALP,20150901,30:12.1,l5,5.34,50000,, HOU.ALP,20150901,30:12.1,l1,5.29,50000,5.3,38000 HOU.ALP,20150901,30:12.1,l2,5.28,50000,5.31,50000 HOU.ALP,20150901,30:12.1,l3,5.27,50000,5.32,50000 HOU.ALP,20150901,30:12.1,l4,5.26,50000,5.33,50000 HOU.ALP,20150901,30:12.1,l5,5.34,50000,, In `for ind, t in enumerate(zip_longest(*[iter(it)] * 4, fillvalue=""), 1)`, _`enumerate`_ with a start index of 1 is keeping track of which _group/level_ we are at. _`zip_longest(*[iter(it)] * 4, fillvalue="")`_ groups the cols into sections i.e `L1-BidPrice,L1-BidSize,L1-AskPrice,L1-AskSize`, `L2-BidPrice,L2-BidSize,L2-AskPrice,L2-AskSize` etc.. all the way to `Ln-..` You have `HOU.ALP 20150901 30:10.8 L1 5.29 50000 5.3 50000` in your expected output but 32000 is the value in your input for `L1-AskSize`, each row has 5 levels and you also have 8 columns so I presume your expected output is wrong.
MAGICS - undefined symbol: _ZTIN5eckit9ExceptionE Question: I'm stuck on a runtime error "undefined symbol: _ZTIN5eckit9ExceptionE" like this Start 2: basic_python 2: Test command: /usr/local/Python/2.7.10/bin/python "coast.py" 2: Environment variables: 2: PYTHONPATH=/opt/src/ecmwf/Magics-2.29.4-Source/build/python 2: LD_LIBRARY_PATH=/opt/src/ecmwf/Magics-2.29.4-Source/build/lib 2: MAGPLUS_HOME=/opt/src/ecmwf/Magics-2.29.4-Source/test/.. 2: OMP_NUM_THREADS=1 2: Test timeout computed to be: 1500 2: Traceback (most recent call last): 2: File "coast.py", line 11, in <module> 2: from Magics.macro import * 2: File "/opt/src/ecmwf/Magics-2.29.4-Source/build/python/Magics/__init__.py", line 32, in <module> 2: _Magics = swig_import_helper() 2: File "/opt/src/ecmwf/Magics-2.29.4-Source/build/python/Magics/__init__.py", line 28, in swig_import_helper 2: _mod = imp.load_module('_Magics', fp, pathname, description) 2: ImportError: /usr/local/Magics/2.29.4/gnu/4.4.7/lib/libMagPlus.so: undefined symbol: _ZTIN5eckit9ExceptionE There was no error while building shared libaray libMagPlus.so. The error just was raised at runtime when Python module loading it. Checked with nm, the undefined symbol '_ZTIN5eckit9ExceptionE' is from a static library libOdb.a, like this nm libOdb.a | grep _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE 0000000000000000 V DW.ref._ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE U _ZTIN5eckit9ExceptionE But there was no any complaint about undefined symbol '_ZTIN5eckit9ExceptionE' for the excutables which linked against the static library libOdb.a directly at the both of complation time and runtime time. All C, Fortran codes also worked well with the static library libOdb.a, except the shared library libMagPlus.so. The library LibMagPlus.so was linked like this /usr/bin/g++ -fPIC -pipe -O2 -g \ -Wl,--disable-new-dtags -shared \ -Wl,-soname,libMagPlus.so -o ../lib/libMagPlus.so \ ... ... \ -Wl,-Bstatic -L$ODB_API/lib -lOdb \ ... ... The library libOdb.a was built like this usr/bin/ar qc ../../lib/libOdb.a ... ... /usr/bin/ranlib ../../lib/libOdb.a Searched the FAQ and Googled, little help with my problem. I knew little about C++, and have no idea how to get this fixed. [ In response to Jorge's inputs, updated these ] Exceptions.h #ifndef eckit_Exceptions_h #define eckit_Exceptions_h #include <errno.h> #include "eckit/eckit.h" #include "eckit/eckit_version.h" #include "eckit/log/CodeLocation.h" #include "eckit/log/Log.h" #include "eckit/log/SavedStatus.h" #include "eckit/compat/StrStream.h" namespace eckit { //----------------------------------------------------------------------------- void handle_panic(const char*); void handle_panic(const char*, const CodeLocation&); /// @brief General purpose exception /// Derive other exceptions from this class and implement then in the class that throws them. class Exception : public std::exception { public: // methods /// Constructor with message Exception(const std::string& what, const CodeLocation& location = CodeLocation() ); /// Destructor /// @throws nothing ~Exception() throw(); virtual const char *what() const throw() { return what_.c_str(); } virtual bool retryOnServer() const { return false; } virtual bool retryOnClient() const { return false; } virtual bool terminateApplication() const { return false; } static bool throwing(); static void exceptionStack(std::ostream&,bool callStack = false); const std::string& callStack() const { return callStack_; } protected: // methods void reason(const std::string&); Exception(); virtual void print(std::ostream&) const; private: // members std::string what_; ///< description std::string callStack_; ///< call stack SavedStatus save_; ///< saved monitor status to recover after destruction Exception* next_; CodeLocation location_; ///< where exception was first thrown friend std::ostream& operator<<(std::ostream& s,const Exception& p) { p.print(s); return s; } }; nm -Cl $ODB_API/lib/libOdb.a | grep -i "eckit::Exception" U eckit::Exception::Exception(std::string const&, eckit::CodeLocation const&) /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:84 U eckit::Exception::~Exception() /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:108 0000000000000000 W eckit::Exception::retryOnClient() const /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:48 0000000000000000 W eckit::Exception::retryOnServer() const /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:47 0000000000000000 W eckit::Exception::terminateApplication() const /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:49 0000000000000000 W eckit::Exception::what() const /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:46 U eckit::Exception::print(std::ostream&) const U typeinfo for eckit::Exception I also tried to unpack all object files from libOdb.a and relink libMagPlus.so with all of them with option '-fvisibility=default -rdynamic', like this ar x libOdb.a ( ./Odb ) /usr/bin/g++ -fvisibility=default -rdynamic -fPIC -pipe -O2 -g \ -Wl,--disable-new-dtags -shared \ -Wl,-soname,libMagPlus.so -o ../lib/libMagPlus.so \ ... ... \ ./Odb/*.o \ ... ... But still got these undefined symbols U eckit::Exception::~Exception() /opt/src/OdbAPI-0.10.2-Source/eckit/src/eckit/exception/Exceptions.h:108 U eckit::Exception::print(std::ostream&) const U typeinfo for eckit::Exception **Wondering if needs to touch Exceptions.h and how to touch it ?** Anybody can help ? Appreciating your time Regards Answer: Take a look at `Exceptions.h` file. Note how all your undefined symbols belong to functions that are **declared but not defined**. ~Exception() throw(); // [...] virtual void print(std::ostream&) const; `eckit::Exception::~Exception()` is your destructor (declared in `Exceptions.h:108` but not defined). The same applies to `eckit::Exception::print(std::ostream&) const`. In the case of `typeinfo for eckit::Exception`, the problem here is that you have virtual functions that are not declared as _pure virtual_ (in abstract classes), but are neither defined, so the type is not complete. If I'm not wrong, as `eckit::Exception` class is meant to be superclass for other derived classes, its destructor should be declared `virtual` too. Check where are those missing functions declared. They should be either in an object file skipped/missed by the archiver (if missing functions are defined in a `.cpp` file) or in a header file that you didn't include (if they are defined in a `.hpp` file). See also: [g++ undefined reference to typeinfo](http://stackoverflow.com/questions/307352/g-undefined-reference-to- typeinfo)
How to use a dict to subset a DataFrame? Question: Say, I have given a DataFrame with most of the columns being categorical data. > data.head() age risk sex smoking 0 28 no male no 1 58 no female no 2 27 no male yes 3 26 no male no 4 29 yes female yes And I would like to subset this data by a dict of key-value pairs for those categorical variables. tmp = {'risk':'no', 'smoking':'yes', 'sex':'female'} Hence, I would like to have the following subset. data[ (data.risk == 'no') & (data.smoking == 'yes') & (data.sex == 'female')] What I want to do is: data[tmp] What is the most python / pandas way of doing this? * * * Minimal example: import numpy as np import pandas as pd from pandas import Series, DataFrame x = Series(random.randint(0,2,50), dtype='category') x.cat.categories = ['no', 'yes'] y = Series(random.randint(0,2,50), dtype='category') y.cat.categories = ['no', 'yes'] z = Series(random.randint(0,2,50), dtype='category') z.cat.categories = ['male', 'female'] a = Series(random.randint(20,60,50), dtype='category') data = DataFrame({'risk':x, 'smoking':y, 'sex':z, 'age':a}) tmp = {'risk':'no', 'smoking':'yes', 'sex':'female'} Answer: You can create a look up data frame from the dictionary and then do an inner join with the `data` which will have the same effect as `query`: from pandas import merge, DataFrame merge(DataFrame(tmp, index =[0]), data) [![enter image description here](https://i.stack.imgur.com/xW4kf.png)](https://i.stack.imgur.com/xW4kf.png)
Is there a way to use itertools in python to clean up nested iterations? Question: Let's say I have the following code: a = [1,2,3] b = [2,4,6] c = [3,5,7] for i in a: for j in b: for k in c: print i * j * k Is there a way I can consolidate an iterator in one line instead of making it nested? Answer: Use `itertools.product` within a list comprehension: In [1]: from itertools import product In [5]: [i*j*k for i, j, k in product(a, b, c)] Out[5]: [6, 10, 14, 12, 20, 28, 18, 30, 42, 12, 20, 28, 24, 40, 56, 36, 60, 84, 18, 30, 42, 36, 60, 84, 54, 90, 126]
imgurpython.helpers.error.ImgurClientRateLimitError: Rate-limit exceeded Question: I have the following error: /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning Traceback (most recent call last): File "download.py", line 22, in <module> search = imgur_client.gallery_search('cat', window='all', sort='time', page=p) File "/usr/local/lib/python2.7/dist-packages/imgurpython/client.py", line 531, in gallery_search response = self.make_request('GET', 'gallery/search/%s/%s/%s' % (sort, window, page), data) File "/usr/local/lib/python2.7/dist-packages/imgurpython/client.py", line 153, in make_request raise ImgurClientRateLimitError() imgurpython.helpers.error.ImgurClientRateLimitError: Rate-limit exceeded! for this code: 1 from imgurpython import ImgurClient 2 import inspect 3 import random 4 import urllib2 5 import requests 6 from imgurpython.helpers.error import ImgurClientError 7 8 client_id = "ABC" 9 client_secret = "ABC" 10 access_token = "ABC" 11 refresh_token = "ABC" 12 13 14 15 image_type = ['jpg', 'jpeg'] 16 17 imgur_client = ImgurClient(client_id, client_secret, access_token, refresh_token) 18 19 item_count = 0 20 for p in range(1, 10000): 21 try: 22 search = imgur_client.gallery_search('cat', window='all', sort='time', page=p) 23 for i in range(0,https://gist.github.com/monajalal/e02792e9a5cbced301a8691b7a62836f len(search)): 24 item_count +=1 25 print(search[i].comment_count) 26 if search[i].comment_count > 10 and not search[i].is_album: 27 print(search[i].type) 28 if search[i].type[6:] in image_type: 29 count = 0 30 try: 31 image_file = urllib2.urlopen(search[i].link, timeout = 5) 32 image_file_name = 'images/'+ search[i].id+'.'+search[i].type[6:] 33 output_image = open(image_file_name, 'wb') 34 output_image.write(image_file.read()) 35 for post in imgur_client.gallery_item_comments(search[i].id, sort='best'): 36 if count <= 10: 37 count += 1 38 output_image.close() 39 except urllib2.URLError as e: 40 print(e) 41 continue 42 except socket.timeout as e: 43 print(e) 44 continue 45 except socket.error as e: 46 print(e) 47 continue 48 except ImgurClientError as e: 49 print(e) 50 continue 51 52 print item_count Also I see this line almost very often: /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning How can I fix the error? Is there any workaround for rate limit error in Imgur? So I am creating this app for academic research use not for commercial and according to <https://api.imgur.com/#limits> it should be free but I had to register my app to get client_id related stuff. How can I set my application as non-commercial so that I would not get this rate limit error or if all kind of applications get this error how should I handle it? How should I set my code so that it would make only 1250 requests per hour? Also here's my credit info: User Limit: 500 User Remaining: 500 User Reset: 2016-10-18 14:32:41 User Client Limit: 12500 User Client Remaining: 9570 UPDATE: With sleep(8) as suggested in the answer I end up with this going on continuously. For different search query this happens at different pages. How can I fix the code so that it would stop executing when this happens? Here's the related code to the update: <https://gist.github.com/monajalal/e02792e9a5cbced301a8691b7a62836f> page number is: 157 0 image/jpeg page number is: 157 0 page number is: 157 0 page number is: 157 /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning /usr/local/lib/python2.7/dist-packages/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning Answer: The rate limit refers to how frequently you're hitting the API, not how many calls you're allowed. To prevent hammering, most APIs have a rate limit (eg: 30 requests per minute, 1 every 2 seconds). Your script is making requests as quickly possible, hundreds or even thousands of times faster than the limit. To prevent your script from hammering, the simplest solution is to introduce a [`sleep`](https://docs.python.org/2/library/time.html#time.sleep) to your for loop. from time import sleep for i in range(10000): print i sleep(2) # seconds Adjust the sleep time to be at least one second greater than what the API defines as its rate limit. <https://api.imgur.com/#limits> > The Imgur API uses a credit allocation system to ensure fair distribution of > capacity. Each application can allow **approximately 1,250 uploads per day > or approximately 12,500 requests per day**. If the daily limit is hit five > times in a month, then the app will be blocked for the rest of the month. > The remaining credit limit will be shown with each requests response in the > `X-RateLimit-ClientRemaining` HTTP header. So 12500 requests / 24 hours is 520 requests per hour or ~8 per minute. That means your sleep should be about 8 seconds long.
Minimize memory overhead in sparse matrix inverse Question: As pretense, I am continuing development in Python 2.7 from a prior question: [Determining a sparse matrix quotient](http://stackoverflow.com/questions/40050947/determining-a-sparse- matrix-quotient) ## My existing code: import scipy.sparse as sp k = sp.csr_matrix(([], ([],[])),shape=[R,R]) denom = sp.csc_matrix(denominator) halfeq = sp.linalg.inv(denom) k = numerator.dot(halfeq) I was successful in calculating for the base `k` and `denom`. Python continued attempting calculation on `halfeq`. The process sat in limbo for aproximately 2 hours before returning an error ## Error Statement: Not enough memory to perform factorization. Traceback (most recent call last): File "<myfilename.py>", line 111, in <module> halfeq = sp.linalg.inv(denom) File "/opt/anaconda/lib/python2.7/site-packages/scipy/sparse/linalg/matfuncs.py", line 61, in inv Ainv = spsolve(A, I) File "/opt/anaconda/lib/python2.7/site-packages/scipy/sparse/linalg/dsolve/linsolve.py", line 151, in spsolve Afactsolve = factorized(A) File "/opt/anaconda/lib/python2.7/site-packages/scipy/sparse/linalg/dsolve/linsolve.py", line 366, in factorized return splu(A).solve File "/opt/anaconda/lib/python2.7/site-packages/scipy/sparse/linalg/dsolve/linsolve.py", line 242, in splu ilu=False, options=_options) MemoryError From the [scipy/smemory.c sourcecode](https://github.com/scipy/scipy/blob/master/scipy/sparse/linalg/dsolve/SuperLU/SRC/smemory.c), the initial statement from the error is found on line 256. I am unable to further analyze the memory defs to determine how to best reallocate memory usage sufficient for execution. For reference, `numerator` has `shape: (552297, 552297)` with `stored elements: 301067607` calculated as `sp.csr_matrix(A.T.dot(Ap))` `denominator` has `shape: (552297, 552297)` with `stored elements: 170837213` calculated as `sp.csr_matrix(A.T.dot(A))` **EDIT** : I've found [a related question on Reddit](https://www.reddit.com/r/Python/comments/3c0m7b/what_is_the_most_precise_way_to_invert_large/), but cannot determine how I would change my equation from `numerator * inv(denominator) = k` Answer: No need to 'preallocate' `k`; this isn't a compiled language. Not that this is costing anything. k = sp.csr_matrix(([], ([],[])),shape=[R,R]) I need to double check this, but I think the `dot/inv` can be replaced by one call to `spsolve`. Remember in the other question I noted that `inv` is `spsolve(A, I)`; denom = sp.csc_matrix(denominator) #halfeq = sp.linalg.inv(denom) #k = numerator.dot(halfeq) k = sp.linalg.spsolve(denom, numerator) That said, it looks like the problem is in the `inv` part, the `factorized(denom)`. While your arrays are sparse, (denom density is 0.00056), they still have a large number of values. Maybe it would help to step back and look at: num = A.T.dot(Ap) den = A.T.dot(A) k = solve(den, num) In other words, review the matrix algebra. (A'*Ap)/(A'*A) I'm little rusty on this. Can we reduce this? Can we partition? Just throwing great big arrays together, even if they are sparse, isn't working. How about providing small `A` and `Ap` arrays that we can use for testing? I'm not interested in testing memory limits, but I'd like to experiment with different calculation methods. The sparse linalg module has a number of iterative solvers. I have no idea whether their memory use is greater or less.
Python: Pandas, dealing with spaced column names Question: If I have multiple text files that I need to parse that look like so, but can vary in terms of column names, and the length of the hashtags above: ![txt.file](https://s4.postimg.org/8p69ptj9p/feafdfdfdfdf.png) How would I go about turning this into a pandas dataframe? I've tried using `pd.read_table('file.txt', delim_whitespace = True, skiprows = 14)`, but it has all sorts of problems. My issues are... All the text, asterisks, and pounds at the top needs to be ignored, but I can't just use skip rows because the size of all the junk up top can vary in length in another file. The columns "stat (+/-)" and "syst (+/-)" are seen as 4 columns because of the whitespace. The one pound sign is included in the column names, and I don't want that. I can't just assign the column names manually because they vary from text file to text file. Any help is much obliged, I'm just not really sure where to go from after I read the file using pandas. Answer: Consider reading in raw file, cleaning it line by line while writing to a new file using `csv` module. Regex is used to identify column headers using the _i_ as match criteria. Below assumes more than one space separates columns: import os import csv, re import pandas as pd rawfile = "path/To/RawText.txt" tempfile = "path/To/TempText.txt" with open(tempfile, 'w', newline='') as output_file: writer = csv.writer(output_file) with open(rawfile, 'r') as data_file: for line in data_file: if re.match('^.*i', line): # KEEP COLUMN HEADER ROW line = line.replace('\n', '') row = line.split(" ") writer.writerow(row) elif line.startswith('#') == False: # REMOVE HASHTAG LINES line = line.replace('\n', '') row = line.split(" ") writer.writerow(row) df = pd.read_csv(tempfile) # IMPORT TEMP FILE df.columns = [c.replace('# ', '') for c in df.columns] # REMOVE '#' IN COL NAMES os.remove(tempfile) # DELETE TEMP FILE
Why additional memory allocation makes multithread Python application work few times faster? Question: I'm writing python module which one of the functions is to check multiple IP addresses if they're active and write this information to database. As those are I/O bound operations I decided to work on multiple threads: * 20 threads for pinging host and checking if it's active (function `check_if_active`) * 5 threads for updating data in database (function `check_if_active_callback`) Program works as followed: 1. Main thread takes IPs from database and puts them to queue `pending_ip` 2. One of 20 threads takes record from `pending_ip` queue, pings host and puts answer to `done_ip` queue 3. One of 5 threads takes record from `done_ip` queue and does update in database if needed What I've observed (during timing tests to get answer how many threads would suit the best in my situation) is that program works aprox. 7-8 times faster if in 5 loops I first declare and start 20+5 threads, delete those objects and then in 6th loop run the program, than if I run program without those additional 5 loops. I suppose this could be somehow related to memory management. Not really sure though if deleting objects makes any sense in python. My questions are: * why is that happening? * how I can achieve this time boost without additional code (and additional memory allocation)? Code: import time, os from threading import Thread from Queue import Queue from readconfig import read_db_config from mysql.connector import Error, MySQLConnection pending_ip = Queue() done_ip = Queue() class Database: connection = MySQLConnection() def connect(self): db_config = read_db_config("mysql") try: self.connection = MySQLConnection(**db_config) except Error as e: print(e) def close_connection(self): if self.connection.is_connected() is True: self.connection.close() def query(self, sqlquery): if self.connection.is_connected() is False: self.connect() try: cursor = self.connection.cursor() cursor.execute(sqlquery) rows = cursor.fetchall() except Error as e: print(e) finally: cursor.close() return rows def update(self,sqlquery, var): if self.connection.is_connected() is False: self.connect() try: cursor = self.connection.cursor() cursor.execute(sqlquery, var) self.connection.commit() except Error as e: self.connection.rollback() print(e) finally: cursor.close() db=Database() def check_if_active(q): while True: host = q.get() response = os.system("ping -c 1 -W 2 %s > /dev/null 2>&1" % (host)) if response == 0: ret = 1 else: ret = 0 done_ip.put((host, ret)) q.task_done() def check_if_active_callback(q, db2): while True: record = q.get() sql = "select active from table where address_ip='%s'" % record[0] rowIP = db2.query(sql) if(rowIP[0][0] != record[1]): sqlupdq = "update table set active=%s where address_ip=%s" updv = (record[1], record[0]) db2.update(sqlupdq, updv) q.task_done() def calculator(): #some irrelevant code rows = db.query("select ip_address from table limit 1000") for row in rows: pending_ip.put(row[0]) #some irrelevant code if __name__ == '__main__': num_threads_pinger = 20 num_threads_pinger_callback = 5 db = Database() for i in range(6): db_pinger_callback =[] worker_p = [] worker_cb = [] #additional memory allocation here in 5 loops for 20 threads for z in range(num_threads_pinger): worker = Thread(target=check_if_active, args=(pending_ip)) worker.setDaemon(True) worker.start() worker_p.append(worker) #additional memory allocation here in 5 loops for 5 threads for z in range(num_threads_pinger_callback): db_pinger_callback.append(Database()) worker = Thread(target=check_if_active_callback, args=(done_ip, db_pinger_callback[z])) worker.setDaemon(True) worker.start() worker_cb.append(worker) if i == 5: start_time = time.time() calculator() pending_ip.join() done_ip.join() print "%s sec" % (time.time() - start_time) #freeing (?) that additional memory for z in range(num_threads_pinger - 1, 0, -1): del worker_p[z] #freeing (?) that additional memory for z in range(num_threads_pinger_callback - 1, 0, -1): db_pinger_callback[z].close_connection() del db_pinger_callback[z] del worker_cb[z] db.close_connection() Answer: In order to give you an exact explanation it would help to know what version of Python you're using. For instance if you're using PyPy then what you've observed is the JIT kicking in after you call your loop 5 times and it just returns a pre-calculated answer. If you're using a standard version of Python then this speed up is due to the interpreter using the compiled byte code from the .pyc files. How it works is basically Python will first create an in memory representation of your code and run it from there. During repeated calls the interpreter will convert some of the more often used code into byte code and store it on disk in .pyc files (this is python byte code similar to java byte code not to be confused with native machine code). Every time you call the same function the interpreter will go to your .pyc files and execute the corresponding byte code this makes the execution much faster as the code you're running is precompiled compared to when you call the function once and python has to parse and interpret your code.
Python SQLite TypeError Question: from sqlite3 import * def insert_record(Who, Invented): connection = connect(database = "activity.db") internet = connection.cursor() list = "INSERT INTO Information VALUES((Alexander_Graham, Phone))" internet.execute(list) rows_inserted = internet.rowcount connection.commit() internet.close() connection.close() #GUI interface from Tkinter import * window = Tk() the_button3 = Button(window, text='Record', command = insert_record).grid(row=1, sticky=W, padx=100,pady=5) window.mainloop() Alright, so what I'm trying to do is when I press the Record button, the values for Information (it have 2 fields called Who and Invented, respectively) in activity.db will add a record Alexander_Graham and Phone. *activity.db is already premade in the same folder as the code But instead I get this error: TypeError: insert_record() takes exactly 2 arguments (0 given) How do I fix it? Answer: insert record is a function that takes two required arguments, which you didn't pass values in for. command = insert_record A good example of this in action is the following test sequence: In [1]: def func(one,two): ...: return one+two ...: In [2]: func() ------------------------------------------------------------------------- -- TypeError Traceback (most recent call last) <ipython-input-2-08a2da4138f6> in <module>() ----> 1 func() TypeError: func() takes exactly 2 arguments (0 given) In [3]: func(1,3) Out[3]: 4 In this function, it fails in the same was as your tk app. You need to provide a function that has default values, or handle it a different way.
Getting HTTP POST Error : {"reason":null,"error":"Request JSON object for insert cannot be null."} Question: I am getting HTTP POST error when I am trying to connect to a Service Now Instance for Change Request Automation using Python. Here is the script I am using with Python 3.4.4 # SNOW CR AUTOMATION SCRIPT import requests import json # put the ip address or dns of your SNOW API in this url url = 'http://<>/change_request.do?JSONv2&sysparm_action=insert' data= { 'short_description': '<value>', 'priority': '<value>', 'reason': '<value>', 'u_reason_for_change': '<value>', 'u_business_driver': '<value>', 'u_plan_of_record_id': '<value>' } print ("Data Inserted :") print (data) #Content type must be included in the header header = {"Authorization":"Basic V1NfRVRPX1ROOkBiY2RlNTQzMjE=","Content- Type":"application/json"} #Performs a POST on the specified url. response = requests.request('POST', url, auth=("<value>","<value>"), json=data, headers=header) print ( " Header is : ") print (response.headers) print (" ") print ( "HTTP Response is :" ) print (response) print (" ") print ("***********************") print (" Output : ") print ( response.text) I am getting an error as below while running the above script. Output : {"reason":null,"error":"Request JSON object for insert cannot be null."} I am not sure why this error is thrown. Can anybody please help on this ? Answer: This is a working example I tested on my instance. I am using REST Table API to insert a change request. It's not true that it can not be http. It's whatever protocol your instance allows to connect, say from browser. #Need to install requests package for python #easy_install requests import requests # Set the request parameters url = '<yourinstance base url>/api/now/table/change_request' user = <username> pwd = <password> # Set proper headers headers = {"Content-Type":"application/json","Accept":"application/json"} # Do the HTTP request response = requests.post(url, auth=(user, pwd), headers=headers ,data="{\"short_description\":\"test in python\"}") # Check for HTTP codes other than 201 if response.status_code != 201: print('Status:', response.status_code, 'Headers:', response.headers, 'Error Response:',response.json()) exit() # Decode the JSON response into a dictionary and use the data data = response.json() print(data)
Error in inserting python variable in mysql table Question: I am working on a raspberry pi project, in which I'm fetching data from plc and storing it into mysql database. Here is my code: import minimalmodbus import serial import mysql.connector instrument = minimalmodbus.Instrument('/dev/ttyAMA0',3,mode='rtu') instrument.serial.baudrate=115200 instrument.serial.parity = serial.PARITY_NONE instrument.serial.bytesize = 8 instrument.serial.stopbits = 1 instrument.serial.timeout = 0.05 con = mysql.connector.connect(user='root',password='raspberry',host='localhost', database='Fujiplc') cursor = con.cursor() try: reg_value=instrument.read_register(102) print reg_value cursor.execute("insert into Register_Values values(%s)",(reg_value)) print ('One row inserted successfully.') except IOError: print("Failed to read from PLC.") print (cursor.rowcount) con.commit() cursor.close() con.close() After running this code, I get next error: Traceback (most recent call last): File "/home/pi/rpi_to_plc_read.py", line 22, in <module> cursor.execute("insert into Register_Values values(%d)",(reg_value)) File "/usr/local/lib/python2.7/dist-packages/mysql/connector/cursor.py", line 477, in execute stmt = operation % self._process_params(params) File "/usr/local/lib/python2.7/dist-packages/mysql/connector/cursor.py", line 355, in _process_params "Failed processing format-parameters; %s" % err) ProgrammingError: Failed processing format-parameters; argument 2 to map() must support iteration I have gone through so many solutions but problem couldn't solve. Please help me. Answer: i think should be. cursor.execute("insert into Register_Values values(%s)",(reg_value)) con.commit()
understanding marshmallow nested schema with list data Question: Am new to python and am usign [marshmallow](https://marshmallow.readthedocs.io/en/latest/) serialization. unable to use the nested scehma. , my code from sqlalchemy import Column, Float, Integer, String, Text, text,ForeignKey from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import relationship Base = declarative_base() metadata = Base.metadata class CompanyDemo(Base): __tablename__ = 'company_demo' company_id = Column(Integer, primary_key=True, server_default=text("nextval('company_demo_company_id_seq'::regclass)")) name = Column(Text, nullable=False) address = Column(String(50)) location = Column(String(50)) class UsersDemo(Base): __tablename__ = 'users_demo' id = Column(Integer, primary_key=True, server_default=text("nextval('users_demo_id_seq'::regclass)")) company_id = Column(Integer,ForeignKey('company_demo.company_id'), nullable=False) email = Column(String) company = relationship('CompanyDemo') schema from marshmallow import Schema, fields, pprint class CompanySchema(Schema): company_id = fields.Int(dump_only=True) name = fields.Str() address = fields.Str() location = fields.Str() class UserSchema(Schema): email = fields.Str() company = fields.Nested(CompanySchema) user = UserSchema() user = UserSchema(many=True) company = CompanySchema() company = CompanySchema(many=True) and my flask app from flask import Flask, jsonify, url_for, render_template from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from flask_sqlalchemy import SQLAlchemy from model import CompanyDemo, UsersDemo from schemas.userschema import user, company app = Flask(__name__) app.secret_key = "shiva" def db_connect(): engine = create_engine('postgresql://[email protected]:5432/test') Session = sessionmaker(autocommit=False, autoflush=False, bind=engine) # create a Session session = Session() session._model_changes = {} return session @app.route('/company', methods=["GET", "POST"]) def get_all_company(): db = db_connect() allcompany = db.query(CompanyDemo).join(UsersDemo).all() return jsonify(company.dump(allcompany, many=True).data) # company is marshmallow schema if __name__ == '__main__': app.run(host='0.0.0.0', port=15418, debug=True) anything wrong in my code? and am facing problem with nested schema and unable to get the nested data in output. the output below > [ { "address": "qqq ", "company_id": 1, "location": "www ", "name": "eee" }, > { "address": "www ", "company_id": 2, "location": "qqq ", "name": "aaa" } ] Answer: Self contained example using in-memory SQLite: from flask import Flask, jsonify from flask.ext.sqlalchemy import SQLAlchemy from marshmallow import Schema, fields, pprint app = Flask(__name__) app.config['DEBUG'] = True app.config['SECRET_KEY'] = 'super-secret' app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///:memory:' app.config['SQLALCHEMY_ECHO'] = True db = SQLAlchemy(app) class CompanyDemo(db.Model): __tablename__ = 'company_demo' company_id = db.Column(db.Integer, primary_key=True) name = db.Column(db.Text, nullable=False) address = db.Column(db.String(50)) location = db.Column(db.String(50)) def __unicode__(self): return u"{name} ({address})".format(name=self.name, address=self.address) class UsersDemo(db.Model): __tablename__ = 'users_demo' id = db.Column(db.Integer, primary_key=True,) company_id = db.Column(db.Integer, db.ForeignKey('company_demo.company_id'), nullable=False) company = db.relationship('CompanyDemo') email = db.Column(db.String) def __unicode__(self): return u"{email}".format(email=self.email) class CompanySchema(Schema): company_id = fields.Int(dump_only=True) name = fields.Str() address = fields.Str() location = fields.Str() class UserSchema(Schema): email = fields.Str() company = fields.Nested(CompanySchema) user_schema = UserSchema() company_schema = CompanySchema() @app.route('/') def index(): return "<a href='/dump_company'>Dump Company</a><br><a href='/dump_user'>Dump User</a>" @app.route('/dump_user') def dump_user(): user = UsersDemo.query.first() return jsonify(user_schema.dump(user).data) @app.route('/dump_company') def dump_company(): company = CompanyDemo.query.first() return jsonify(company_schema.dump(company).data) def build_db(): db.drop_all() db.create_all() company = CompanyDemo(name='Test 1', address='10 Downing Street', location='wherever') db.session.add(company) user = UsersDemo(email='[email protected]', company=company) db.session.add(user) db.session.commit() @app.before_first_request def first_request(): build_db() if __name__ == '__main__': app.run(debug=True, port=7777)
NetworkX: how to properly create a dictionary of edge lengths? Question: Say I have a regular grid network made of `10x10` nodes which I create like this: import networkx as nx from pylab import * import matplotlib.pyplot as plt %pylab inline ncols=10 N=10 #Nodes per side G=nx.grid_2d_graph(N,N) labels = dict( ((i,j), i + (N-1-j) * N ) for i, j in G.nodes() ) nx.relabel_nodes(G,labels,False) inds=labels.keys() vals=labels.values() inds=[(N-j-1,N-i-1) for i,j in inds] posk=dict(zip(vals,inds)) nx.draw_networkx(G, pos=posk, with_labels=True, node_size = 150, node_color='blue',font_size=10) plt.axis('off') plt.title('Grid') plt.show() Now say I want to create a dictionary which stores, for each edge, its length. This is the intended outcome: d={(0,1): 3.4, (0,2): 1.7, ...} And this is how I try to get to that point: from math import sqrt lengths={G.edges(): math.sqrt((x-a)**2 + (y-b)**2) for (x,y),(a,b) in G.edges()} But there clearly is something wrong as I get the following error message: --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-7-c73c212f0d7f> in <module>() 2 from math import sqrt 3 ----> 4 lengths={G.edges(): math.sqrt((x-a)**2 + (y-b)**2) for (x,y),(a,b) in G.edges()} 5 6 <ipython-input-7-c73c212f0d7f> in <dictcomp>(***failed resolving arguments***) 2 from math import sqrt 3 ----> 4 lengths={G.edges(): math.sqrt((x-a)**2 + (y-b)**2) for (x,y),(a,b) in G.edges()} 5 6 TypeError: 'int' object is not iterable **What am I missing?** Answer: There is a lot going wrong in the last line, first and foremost that G.edges() is an iterator and not a valid dictionary key, and secondly, that G.edges() really just yields the edges, not the positions of the nodes. This is what you want instead: lengths = dict() for source, target in G.edges(): x1, y1 = posk[source] x2, y2 = posk[target] lengths[(source, target)] = math.sqrt((x2-x1)**2 + (y2-y1)**2)
Why df[[2,3,4]][2:4] works and df[[2:4]][2:4] does not in Python Question: suppose we have a datarame import pandas as pd df = pd.read_csv('...') df 0 1 2 3 4 0 1 2 3 4 5 1 1 2 3 4 5 2 1 2 3 4 5 3 1 2 3 4 5 4 1 2 3 4 5 Why one approach is working and other returns syntax error? Answer: I think you need [`ix`](http://pandas.pydata.org/pandas- docs/stable/generated/pandas.DataFrame.ix.html): print (df.ix[2:4,2:4]) 2 3 2 3 4 3 3 4 4 3 4
Running the sample code in pytesseract Question: I am running python 2.6.6 and want to install the [pytesseract](https://pypi.python.org/pypi/pytesseract) package. After extraction and installation, I can call the pytesseract from the command line. However I want to run the tesseract within python. I have the following code (ocr.py): try: import Image except ImportError: from PIL import Image import pytesseract print(pytesseract.image_to_string(Image.open('test.png'))) print(pytesseract.image_to_string(Image.open('test-european.jpg'),lang='fra')) When I run the code by python ocr.py, I get the following output: Traceback (most recent call last): File "ocr.py", line 6, in <module> print(pytesseract.image_to_string(Image.open('test.png'))) File "/pytesseract-0.1.6/build/lib/pytesseract/pytesseract.py", line 164, in image_to_string raise TesseractError(status, errors) pytesseract.TesseractError: (2, 'Usage: python tesseract.py [-l language] input_file') test.png and test-european.jpg are in the working directory. Can Someone help me running this code? I have tried the following: 1. Adjusted the tesseract_cmd to 'pytesseract' 2. Installed tesseract-ocr Any help is appreciated as I am trying to solve this problem for hours now. Answer: `tesseract_cmd` should point to the command line program [`tesseract`](https://github.com/tesseract-ocr/tesseract), not `pytesseract`. For instance on Ubuntu you can install the program using: sudo apt install tesseract-ocr And then set the variable to just `tesseract` or `/usr/bin/tesseract`.
Python cprofiler a function Question: How to profile one function with cprofiler? label = process_one(signature) become import cProfile label = cProfile.run(process_one(signature)) but it didn't work :/ Answer: according to documentation (<https://docs.python.org/2/library/profile.html>) it should be `cProfile.run('process_one(signature)')` also, look at the answer <http://stackoverflow.com/a/17259420/1966790>
Reading files with hdfs3 fails Question: I am trying to read a file on HDFS with Python using the hdfs3 module. import hdfs3 hdfs = hdfs3.HDFileSystem(host='xxx.xxx.com', port=12345) hdfs.ls('/projects/samplecsv/part-r-00000') This produces [{'block_size': 134345348, 'group': 'supergroup', 'kind': 'file', 'last_access': 1473453452, 'last_mod': 1473454723, 'name': '/projects/samplecsv/part-r-00000/', 'owner': 'dr', 'permissions': 420, 'replication': 3, 'size': 98765631}] So it seems to be able to access the HDFS and read the directory structure. However, reading the file fails. with hdfs.open('/projects/samplecsv/part-r-00000', 'rb') as f: print(f.read(100)) gives --------------------------------------------------------------------------- OSError Traceback (most recent call last) . .<snipped> . OSError: [Errno Read file /projects/samplecsv/part-r-00000 Failed:] 1 What could be the issue? I am using Python3.5. Answer: if You want any operation on files then you have to pass full File path . import hdfs3 hdfs = hdfs3.HDFileSystem(host='xxx.xxx.com', port=12345) hdfs.ls('/projects/samplecsv/part-r-00000') #you have to add file to location hdfs.put('local-file.txt', '/projects/samplecsv/part-r-00000') with hdfs.open('projects/samplecsv/part-r-00000/local-file.txt', 'rb') as f: print(f.read(100))
find repeated element in list of list python Question: I have been struggling with this problem for two days and I need help with it. I need to find repeated element in a list of lists `list_of_list = [(a1, b1, c1), (a2, b2, c2), ..., (an, bn, cn)]` where "a" and "b" elements are integers and "c" elements are floats. So if for example `a1 == a2` or `a1 == bn`, I need to create a new list with the entire list elements and I need to iterate this for all the lists (a, b, c) in the list of lists. To put it another way, I need all lists that have elements that are present in more than one list. I need to compare only "a" and "b" elements but obtain the associated value "c" in the final list. For example: list_of_list = [(1, 2, 4.99), (3, 6, 5.99), (1, 4, 3.00), (5, 1, 1.12), (7, 8, 1.99) ] desired_result=[(1, 2, 4.99), (1, 4, 3.00), (5, 1, 1.12)] I try many ideas...but nothing nice came up: MI_network = [] #repeated elements list genesis = list(complete_net) #clon to work on genesis_next = list(genesis) #clon to remove elements in iterations genesis_next.remove(genesis_next[0]) while genesis_next != []: for x in genesis: if x[0] in genesis_next and x[1] not in genesis_next: MI_network.append(x) if x[0] not in genesis_next and x[1] in genesis_next: MI_network.append(x) genesis_next.remove(genesis_next[0]) Answer: You can count occurrences of specific list elements and take lists with counts > 1. Something like this, using `collections.defaultdict()`: >>> from collections import defaultdict >>> count = defaultdict(int) >>> for lst in list_of_list: ... count[lst[0]] += 1 ... count[lst[1]] += 1 ... >>> [lst for lst in list_of_list if count[lst[0]] > 1 or count[lst[1]] > 1] [(1, 2, 4.99), (1, 4, 3.0), (5, 1, 1.12)]
Python/Flask: UnicodeDecodeError/ UnicodeEncodeError: 'ascii' codec can't decode/encode Question: Sorry for the millionth question about this, but I've read so much about the topic and still don't get this error fixed (newbie to all of this). I'm trying to display the content of a postgres table on a website with flask (using Ubuntu 16.04/python 2.7.12). There are non-ascii characters in the table ('ü' in this case) and the result is a UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2: ordinal not in range(128). This is what my **init**.py looks like: #-*- coding: utf-8 -*- from flask import Blueprint, render_template import psycopg2 from .forms import Form from datetime import datetime from .table import Item, ItemTable test = Blueprint('test', __name__) def init_test(app): app.register_blueprint(test) def createTable(cur): cmd = "select * from table1 order by start desc;" cur.execute(cmd) queryResult = cur.fetchall() items = [] table = 'table could not be read' if queryResult is not None: for row in range(0, len(queryResult)): items.append(Item(queryResult[row][0], queryResult[row][1].strftime("%d.%m.%Y"), queryResult[row][2].strftime("%d.%m.%Y"), \ queryResult[row][1].strftime("%H:%M"), queryResult[row][2].strftime("%H:%M"), \ queryResult[row][3], queryResult[row][4], queryResult[row][5], queryResult[row][6])) table = ItemTable(items) return table @test.route('/test') def index(): dbcon = psycopg2.connect("dbname=testdb user=postgres host=localhost") cur = dbcon.cursor() table = createTable(cur) cur.close() return render_template('test_index.html', table=table) And part of the html-file: {% extends "layout.html" %} {% block head %}Title{% endblock %} {% block body %} <script type="text/javascript" src="{{ url_for('static', filename='js/bootstrap.js') }}"></script> <link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='css/custom.css') }}"> <div class="row" id="testid"> {{table}} </div> {% endblock %}{# Local Variables: coding: utf-8 End: #} The problem is in queryResult[row][6] which is the only row in the table with strings, the rest is integers. The encoding of the postgres database is utf-8. The type of queryResult[row][6] returns type 'str'. What I read [here](http://initd.org/psycopg/docs/usage.html#unicode-handling) is that the string should be encoded in utf-8, as that is the encoding of the database client. Well, that doesn't seem to work!? Then I added the line psycopg2.extensions.register_type(psycopg2.extensions.UNICODE) to force the result to be unicode (type of queryResult[row][6] returned type 'unicode'), because as was recommended [here](http://stackoverflow.com/questions/5120302/avoiding-python- unicodedecodeerror-in-jinjas-nl2br-filter), I tried to stick to unicode everywhere. Well that resulted in a UnicodeEncodeError: 'ascii' codec can't encode character u'\xfc' in position 2: ordinal not in range(128). Then I thought, maybe something went wrong with converting to string (bytes) before and I tried to do it myself then with writing queryResult[row][6].encode('utf-8', 'replace') which led to an UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2: ordinal not in range(128). Didn't even work with 'ignore' instead of 'replace'. What is going on here? I checked if the render_template() has a problem with unicode by creating and passing a variable v=u'ü', but that was no problem and was displayed correctly. Yeah, I read the usual recommended stuff like nedbatchelder.com/text/unipain.html and Unicode Demystified, but that didn't help me solve my problem here, I'm obviously missing something. Here is a traceback of the first UnicodeDecodeError: File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 2000, in __call__ return self.wsgi_app(environ, start_response) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1991, in wsgi_app response = self.make_response(self.handle_exception(e)) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1567, in handle_exception reraise(exc_type, exc_value, tb) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1988, in wsgi_app response = self.full_dispatch_request() File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1641, in full_dispatch_request rv = self.handle_user_exception(e) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1544, in handle_user_exception reraise(exc_type, exc_value, tb) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1639, in full_dispatch_request rv = self.dispatch_request() File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/app.py", line 1625, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "/home/name/Desktop/testFlask/app/test/__init__.py", line 95, in index return render_template('test_index.html', table=table) #, var=var File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/templating.py", line 134, in render_template context, ctx.app) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask/templating.py", line 116, in _render rv = template.render(context) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/jinja2/environment.py", line 989, in render return self.environment.handle_exception(exc_info, True) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/jinja2/environment.py", line 754, in handle_exception reraise(exc_type, exc_value, tb) File "/home/name/Desktop/testFlask/app/templates/test_index.html", line 1, in top-level template code {% extends "layout.html" %} File "/home/name/Desktop/testFlask/app/templates/layout.html", line 40, in top-level template code {% block body %}{% endblock %} File "/home/name/Desktop/testFlask/app/templates/test_index.html", line 7, in block "body" {{table}} File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/table.py", line 86, in __html__ tbody = self.tbody() File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/table.py", line 103, in tbody out = [self.tr(item) for item in self.items] File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/table.py", line 120, in tr ''.join(c.td(item, attr) for attr, c in self._cols.items() File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/table.py", line 121, in <genexpr> if c.show)) File "/home/name/Desktop/testFlask/app/test/table.py", line 7, in td self.td_contents(item, self.get_attr_list(attr))) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/columns.py", line 99, in td_contents return self.td_format(self.from_attr_list(item, attr_list)) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/flask_table/columns.py", line 114, in td_format return Markup.escape(content) File "/home/name/Desktop/testFlask/venv/lib/python2.7/site-packages/markupsafe/__init__.py", line 165, in escape rv = escape(s) Any help is greatly appreciated... Answer: since in Python 2 bytecode is not enforced, one can get confused with them. Encoding and Decoding works as far as i know from string to bytecode and reverse. So if your resultset is a string, there should be no need to encode it again. If you get wrong representations for special characters like "§", i would try something like this: repr(queryResult[row][6])). Does that work?
Identify drive letter of USB composite device using Python Question: I have a USB composite device that has an SD card. Using Python, I need a way to find the drive letter of the SD card when the device is connected. Does anyone have experience with this? Initially it needs to work in Windows, but I'll eventually need to port it to Mac and Linux. Answer: I don't have an SD card attached to a USB port. To get you started, you could _try_ this on Windows. Install [Golden's WMI](http://timgolden.me.uk/python/wmi/index.html). I found that the Windows .zip wouldn't install but the pip version works fine, or at least it does on Win7. Then you can list logical disks with code like this. >>> import wmi >>> c=wmi.WMI() ... >>> for disk in c.Win32_LogicalDisk(): ... print(disk) This code provided a listing that included mention of a NAS which is why I have hopes for your SD card. Various refinements are possible.
Convert .fbx to .obj with Python FBX SDK Question: I have a ten frame .fbx file of an animal walking. This file includes a rigged model with textures, but I am only interested in the mesh of the model at each frame. How can I use Python FBX SDK or Python Blender SDK to export each frame of the fbx file into an obj file? Am I approaching this the wrong way? Should I try to find a way to do this manually in Maya/Blender first? Answer: its a example for fbx to obj import fbx # Create an SDK manager manager = fbx.FbxManager.Create() # Create a scene scene = fbx.FbxScene.Create(manager, "") # Create an importer object importer = fbx.FbxImporter.Create(manager, "") # Path to the .obj file milfalcon = "samples/millenium-falcon/millenium-falcon.fbx" # Specify the path and name of the file to be imported importstat = importer.Initialize(milfalcon, -1) importstat = importer.Import(scene) # Create an exporter object exporter = fbx.FbxExporter.Create(manager, "") save_path = "samples/millenium-falcon/millenium-falcon.obj" # Specify the path and name of the file to be imported exportstat = exporter.Initialize(save_path, -1) exportstat = exporter.Export(scene)
How to tell Python to save files in this folder? Question: I am new to Python and have been assigned the task to clean up the files in Slack. I have to backup the files and save them to the designated folder Z drive Slack Files and I am using the open syntax below but it is producing the permission denied error for it. This script has been prepared by my senior to finish up this job. from slacker import * import sys import time import os from datetime import timedelta, datetime root = 'Z:\Slack_Files' def main(token, weeks=4): slack = Slacker(token) total = slack.files.list(count=1).body['paging']['total'] num_pages = int(total/1000.00 + 1) print("{} files to be processed, across {} pages".format(total, num_pages)) files_to_delete = [] ids = [] count = 1 for page in range(num_pages): print ("Pulling page number {}".format(page + 1)) files = slack.files.list(count=1000, page=page+1).body['files'] for file in files: print("Checking file number {}".format(count)) if file['id'] not in ids: ids.append(file['id']) if datetime.fromtimestamp(file['timestamp']) < datetime.now() - timedelta(weeks=weeks): files_to_delete.append(file) print("File No. {} will be deleted".format(count)) else: print ("File No. {} will not be deleted".format(count)) count+=1 print("All files checked\nProceeding to delete files") print("{} files will be deleted!".format(len(files_to_delete))) count = 1 for file in files_to_delete: # print open('Z:\Slack_Files') print("Deleting file {} of {} - {}".format(count, len(files_to_delete), file["name"])) print(file["name"]) count+=1 return count-1 for fn in os.listdir(r'Z:\Slack_Files'): if os.path.isfile(fn): open(fn,'r') if __name__ == "__main__": try: token = '****' except IndexError: print("Usage: python file_deleter.py api_token\nPlease provide a value for the API Token") sys.exit(2) main(token) The error it displays is: Traceback (most recent call last): File "C:\Users\Slacker.py", line 55, in <module> main(token) File "C:\Users\Slacker.py", line 39, in main print open('Z:\Slack_Files') IOError: [Errno 13] Permission denied: 'Z:\\Slack_Files' Answer: To iterate over files in a particular folder, we can simply use os.listdir() to traverse a single tree. import os for fn in os.listdir(r'Z:\Slack_Files'): if os.path.isfile(fn): open(fn,'r') # mode is r means read mode
Ipython cv2.imwrite() not saving image Question: I have written a code in python opencv. I am trying to write the processed image back to disk but the image is not getting saved and it is not showing any error(runtime and compilation) The code is """ Created on Wed Oct 19 18:07:34 2016 @author: Niladri """ import numpy as np import cv2 if __name__ == '__main__': import sys img = cv2.imread('C:\Users\Niladri\Desktop\TexturesCom_LandscapeTropical0080_2_S.jpg') if img is None: print 'Failed to load image file:' sys.exit(1) gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) h, w = img.shape[:2] eigen = cv2.cornerEigenValsAndVecs(gray, 15, 3) eigen = eigen.reshape(h, w, 3, 2) # [[e1, e2], v1, v2] #flow = eigen[:,:,2] iter_n = 10 sigma = 5 str_sigma = 3*sigma blend = 0.5 img2 = img for i in xrange(iter_n): print i, gray = cv2.cvtColor(img2, cv2.COLOR_BGR2GRAY) eigen = cv2.cornerEigenValsAndVecs(gray, str_sigma, 3) eigen = eigen.reshape(h, w, 3, 2) # [[e1, e2], v1, v2] x, y = eigen[:,:,1,0], eigen[:,:,1,1] print eigen gxx = cv2.Sobel(gray, cv2.CV_32F, 2, 0, ksize=sigma) gxy = cv2.Sobel(gray, cv2.CV_32F, 1, 1, ksize=sigma) gyy = cv2.Sobel(gray, cv2.CV_32F, 0, 2, ksize=sigma) gvv = x*x*gxx + 2*x*y*gxy + y*y*gyy m = gvv < 0 ero = cv2.erode(img, None) dil = cv2.dilate(img, None) img1 = ero img1[m] = dil[m] img2 = np.uint8(img2*(1.0 - blend) + img1*blend) #print 'done' cv2.imshow('dst_rt', img2) cv2.waitKey(0) cv2.destroyAllWindows() #cv2.imwrite('C:\Users\Niladri\Desktop\leaf_image_shock_filtered.jpg', img2) for i in xrange(iter_n): print i, gray = cv2.cvtColor(img2, cv2.COLOR_BGR2GRAY) eigen = cv2.cornerEigenValsAndVecs(gray, str_sigma, 3) eigen = eigen.reshape(h, w, 3, 2) # [[e1, e2], v1, v2] x, y = eigen[:,:,1,0], eigen[:,:,1,1] print eigen gxx = cv2.Sobel(gray, cv2.CV_32F, 2, 0, ksize=sigma) gxy = cv2.Sobel(gray, cv2.CV_32F, 1, 1, ksize=sigma) gyy = cv2.Sobel(gray, cv2.CV_32F, 0, 2, ksize=sigma) gvv = x*x*gxx + 2*x*y*gxy + y*y*gyy m = gvv < 0 ero = cv2.erode(img, None) dil = cv2.dilate(img, None) img1 = dil img1[m] = ero[m] img2 = np.uint8(img2*(1.0 - blend) + img1*blend) print 'done' #cv2.imwrite('D:\IP\tropical_image_sig5.bmp', img2) cv2.imshow('dst_rt', img2) cv2.waitKey(0) cv2.destroyAllWindows() #cv2.imshow('dst_rt', img2) cv2.imwrite('C:\Users\Niladri\Desktop\tropical_image_sig5.bmp', img2) Can anyone please tell me why it is not working. cv2.imshow is working properly(as it is showing the correct image). Thanks and Regards Niladri Answer: As a general and absolute rule, you _have_ to protect your windows path strings (containing backslashes) with `r` prefix or some characters are interpreted (ex: `\n,\b,\v,\x` aaaaand `\t` !): so when doing this: cv2.imwrite('C:\Users\Niladri\Desktop\tropical_image_sig5.bmp', img2) you're trying to save to `C:\Users\Niladri\Desktop<TAB>ropical_image_sig5.bmp` (and I really don't know what it does :)) Do this: cv2.imwrite(r'C:\Users\Niladri\Desktop\tropical_image_sig5.bmp', img2) Note: the read works fine because "escaped" uppercase letters have no particular meaning in python 2 (`\U` has a meaning in python 3)
how do i find my ipv4 using python? Question: my server copy it if you want! :) how do i find my ipv4 using python? can i you try to keep it real short? import socket def Main(): host = '127.0.0.1' port = 5000 s = socket.socket() s.bind((host,port)) s.listen(1) c1, addr1 = s.accept() sending = "Connection:" + str(addr1) connection = (sending) print(connection) s.listen(1) c2, addr2 = s.accept() sending = "Connection:" + str(addr2) connection = (sending) print(connection) while True: data1 = c1.recv(1024).decode('utf-8') data2 = c2.recv(1024).decode('utf-8') if not data1: break if not data2: break if data2: c1.send(data2.encode('utf-8')) if data1: c2.send(data1.encode('utf-8')) s.close() if __name__== '__main__': Main() thx for the help i appreciate it! Answer: That's all you need for the local address (returns a string): socket.gethostbyname(socket.gethostname())
Drawing on python and pycharm Question: I am a beginner on Python. I draw a square with this code. import turtle square=turtle.Turtle() print(square) for i in range(4): square.fd(100) square.lt(90) turtle.mainloop() However, there is another code for drawing square with this code in the book. Apparently, I tried to copy the exact same thing but it didn't work out. Can someone help me to figure out the problem? def drawSquare(t,sz): """Make turtle t draw a square of sz.""" for i in range(4): t.forward(sz) t.left(90) turtle.mainloop() Answer: You need to call the function so it will start: import turtle def drawSquare(t, size): for i in range(4): t.forward(size) t.left(90) turtle.mainloop() drawSquare(turtle.Turtle(), 100)
Work with a row in a pandas dataframe without incurring chain indexing (not coping just indexing) Question: My data is organized in a dataframe: import pandas as pd import numpy as np data = {'Col1' : [4,5,6,7], 'Col2' : [10,20,30,40], 'Col3' : [100,50,-30,-50], 'Col4' : ['AAA', 'BBB', 'AAA', 'CCC']} df = pd.DataFrame(data=data, index = ['R1','R2','R3','R4']) Which looks like this (only much bigger): Col1 Col2 Col3 Col4 R1 4 10 100 AAA R2 5 20 50 BBB R3 6 30 -30 AAA R4 7 40 -50 CCC My algorithm loops through this table rows and performs a set of operations. For cleaness/lazyness sake, I would like to work on a single row at each iteration without typing `df.loc['row index', 'column name']` to get each cell value I have tried to follow the [right style](http://pandas.pydata.org/pandas- docs/stable/indexing.html#indexing-view-versus-copy) using for example: row_of_interest = df.loc['R2', :] However, I still get the warning when I do: row_of_interest['Col2'] = row_of_interest['Col2'] + 1000 SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame And it is not working (as I intended) it is making a copy print df Col1 Col2 Col3 Col4 R1 4 10 100 AAA R2 5 20 50 BBB R3 6 30 -30 AAA R4 7 40 -50 CCC Any advice on the proper way to do it? Or should I just stick to work with the data frame directly? Edit 1: Using the replies provided the warning is removed from the code but the original dataframe is not modified: The "row of interest" `Series` is a copy not part of the original dataframe. For example: import pandas as pd import numpy as np data = {'Col1' : [4,5,6,7], 'Col2' : [10,20,30,40], 'Col3' : [100,50,-30,-50], 'Col4' : ['AAA', 'BBB', 'AAA', 'CCC']} df = pd.DataFrame(data=data, index = ['R1','R2','R3','R4']) row_of_interest = df.loc['R2'] row_of_interest.is_copy = False new_cell_value = row_of_interest['Col2'] + 1000 row_of_interest['Col2'] = new_cell_value print row_of_interest Col1 5 Col2 1020 Col3 50 Col4 BBB Name: R2, dtype: object print df Col1 Col2 Col3 Col4 R1 4 10 100 AAA R2 5 20 50 BBB R3 6 30 -30 AAA R4 7 40 -50 CCC Edit 2: This is an example of the functionality I would like to replicate. In python a list of lists looks like: a = [[1,2,3],[4,5,6]] Now I can create a "label" b = a[0] And if I change an entry in b: b[0] = 7 Both a and b change. print a, b [[7,2,3],[4,5,6]], [7,2,3] Can this behavior be replicated between a pandas dataframe labeling one of its rows a pandas series? Answer: This should work: row_of_interest = df.loc['R2', :] row_of_interest.is_copy = False row_of_interest['Col2'] = row_of_interest['Col2'] + 1000 Setting `.is_copy = False` is the trick Edit 2: import pandas as pd import numpy as np data = {'Col1' : [4,5,6,7], 'Col2' : [10,20,30,40], 'Col3' : [100,50,-30,-50], 'Col4' : ['AAA', 'BBB', 'AAA', 'CCC']} df = pd.DataFrame(data=data, index = ['R1','R2','R3','R4']) row_of_interest = df.loc['R2'] row_of_interest.is_copy = False new_cell_value = row_of_interest['Col2'] + 1000 row_of_interest['Col2'] = new_cell_value print row_of_interest df.loc['R2'] = row_of_interest print df df: Col1 Col2 Col3 Col4 R1 4 10 100 AAA R2 5 1020 50 BBB R3 6 30 -30 AAA R4 7 40 -50 CCC
'DataFrame' object is not callable Question: I'm trying to create a heatmap using Python on Pycharms. I've this code: import numpy as np import pandas as pd import matplotlib matplotlib.use('agg') import matplotlib.pyplot as plt data1 = pd.read_csv(FILE") freqMap = {} for line in data1: for item in line: if not item in freqMap: freqMap[item] = {} for other_item in line: if not other_item in freqMap: freqMap[other_item] = {} freqMap[item][other_item] = freqMap[item].get(other_item, 0) + 1 freqMap[other_item][item] = freqMap[other_item].get(item, 0) + 1 df = data1[freqMap].T.fillna(0) print(df) My data is stored into a CSV file. Each row represents a sequence of products that are associated by a Consumer Transaction.The typically Basket Market Analysis: 99 32 35 45 56 58 7 72 99 45 51 56 58 62 72 17 55 56 58 62 21 99 35 21 99 44 56 58 7 72 72 17 99 35 45 56 7 56 62 72 21 91 99 35 99 35 55 56 58 62 72 99 35 51 55 58 7 21 99 56 58 62 72 21 55 56 58 21 99 35 99 35 62 7 17 21 62 72 21 99 35 58 56 62 72 99 32 35 72 17 99 55 56 58 When I execute the code, I'm getting the following error: Traceback (most recent call last): File "C:/Users/tst/PycharmProjects/untitled1/tes.py", line 22, in <module> df = data1[freqMap].T.fillna(0) File "C:\Users\tst\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 1997, in __getitem__ return self._getitem_column(key) File "C:\Users\tst\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 2004, in _getitem_column return self._get_item_cache(key) File "C:\Users\tst\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\generic.py", line 1348, in _get_item_cache res = cache.get(item) TypeError: unhashable type: 'dict' How can I solve this problem? Many thanks! Answer: You are reading a csv file but it has no header, the delimiter is a space not a comma, and there are a variable number of columns. So that is three mistakes in your first line. And data1 is a DataFrame, freqMap is a dictionary that is completely unrelated. So it makes no sense to do data1[freqMap]. I suggest you step through this line by line in jupyter or a python interpreter. Then you can see what each line actually does and experiment.
Reformat JSON file? Question: I have two JSON files. File A: "features": [ { "attributes": { "NAME": "R T CO", "LTYPE": 64, "QUAD15M": "279933", "OBJECTID": 225, "SHAPE.LEN": 828.21510830520401 }, "geometry": { "paths": [ [ [ -99.818614674337155, 27.782542677671653 ], [ -99.816056346719051, 27.782590806976135 ] ] ] } } File B: "features": [ { "geometry": { "type": "MultiLineString", "coordinates": [ [ [ -99.773315512624, 27.808875128096 ], [ -99.771397939251, 27.809512259374 ] ] ] }, "type": "Feature", "properties": { "LTYPE": 64, "SHAPE.LEN": 662.3800009247, "NAME": "1586", "OBJECTID": 204, "QUAD15M": "279933" } }, I would like File B to be reformatted to look like File A. Change "properties" to "attributes", "coordinates" to "paths", and remove both "type": "MultiLineString" and "type": "Feature". What is the best way to do this via python? Is there a way to also reorder the "attributes" key value pairs to look like File A? It's a rather large dataset and I would like to iterate through the entire file. Answer: Manipulating JSON in Python is a good candidate for the [input-process-output model](https://en.wikipedia.org/wiki/IPO_model) of programming. For input, you convert the external JSON file into a Python data structure, using [`json.load()`](https://docs.python.org/2/library/json.html#json.load). For output, you convert the Python data structure into an external JSON file using [`json.dump()`](https://docs.python.org/2/library/json.html#json.dump). For the processing or conversion step, do whatever it is that you need to do, using ordinary Python `dict` and `list` methods. This program might do what you want: import json with open("b.json") as b: b = json.load(b) for feature in b["features"]: feature["attributes"] = feature["properties"] del feature["properties"] feature["geometry"]["paths"] = feature["geometry"]["coordinates"] del feature["geometry"]["coordinates"] del feature["geometry"]["type"] del feature["type"] with open("new-b.json", "w") as new_b: json.dump(b, new_b, indent=1, separators=(',', ': '))
How to execute multiline python code from a bash script? Question: I need to extend a shell script (bash). As I am much more familiar with python I want to do this by writing some lines of python code which depends on variables from the shell script. Adding an extra python file is not an option. result=`python -c "import stuff; print('all $code in one very long line')"` is not very readable. I would prefer to specify my python code as a multiline string and then execute it. Answer: Use a here-doc: result=$(python <<EOF import stuff print('all $code in one very long line') EOF )