Question: Like there is a folder say XYZ , whcih contain files with diffrent diffrent format
let say .txt file, excel file, .py file etc.
i want to display in the output all file name using Python programming

Answer: 
Here is an example that might also help show some of the handy basics of python -- dicts `{}` , lists `[]` , little string techniques (`split`), a module like `os`, etc.:

```
bvm@bvm:~/example$ ls
deal.xls    five.xls  france.py  guido.py    make.py      thing.mp3  work2.doc
example.py  four.xls  fun.mp3    letter.doc  thing2.xlsx  what.docx  work45.doc
bvm@bvm:~/example$ python
>>> import os
>>> files = {}
>>> for item in os.listdir('.'):
...     try:
...             files[item.split('.')[1]].append(item)
...     except KeyError:
...             files[item.split('.')[1]] = [item]
... 
>>> files
{'xlsx': ['thing2.xlsx'], 'docx': ['what.docx'], 'doc': ['letter.doc', 
'work45.doc', 'work2.doc'], 'py': ['example.py', 'guido.py', 'make.py', 
'france.py'], 'mp3': ['thing.mp3', 'fun.mp3'], 'xls': ['five.xls',
'deal.xls', 'four.xls']}
>>> files['doc']
['letter.doc', 'work45.doc', 'work2.doc']
>>> files['py']
['example.py', 'guido.py', 'make.py', 'france.py']

```

For your update question, you might try something like:

```
>>> for item in enumerate(os.listdir('.')):
...     print item
... 
(0, 'thing.mp3')
(1, 'fun.mp3')
(2, 'example.py')
(3, 'letter.doc')
(4, 'five.xls')
(5, 'guido.py')
(6, 'what.docx')
(7, 'work45.doc')
(8, 'deal.xls')
(9, 'four.xls')
(10, 'make.py')
(11, 'thing2.xlsx')
(12, 'france.py')
(13, 'work2.doc')
>>>

```
```
import os

XYZ = '.'

for item in enumerate(sorted(os.listdir(XYZ))):
    print item

```