improvement : Peewee Cookbook 
http://peewee.readthedocs.org/en/unstable-2.0/peewee/cookbook.html

there is example on use pwiz.py

```
python pwiz.py my_postgresql_database
```

I suggest to replace such things with 

```
python -m pwiz my_postgresql_database
```

It's better to explicitly search for python module in python libs than "some script" in system paths.
Also in my case it said evident thing:

```
$ python pwiz.py     
python: can't open file 'pwiz.py': [Errno 2] No such file or directory
```
