Instructions

1. Clone this repository
2. Create the following exrecise in ext_info.py.
3. Don't forget to add, commit and push your work.
4. Send your repo url to via https://hackita02.hasadna.org.il/sa/

File Information By Extension (Python Standard Library Exercise)

Create a command line program that shows information about different file types in a specified folder. For example:

:::bash
$ python ext_info.py .
png 16 2765632
py 1 2103
pyc 1 608
txt 10 34042
zip 3 4540097

$ python ext_info.py /home/udi/music/
m3u 12 97633
mp3 52 83654229

In the first example the current folder was checked (by specifying . on the command line as the parameter). 16 files with the "png" extension were found, with a total size of 2765632 bytes.

Implementation notes:

• Subfolders should be ignored.

• "jpg" and "JPG" are considered different extensions.

• Files with no extensions should include the '.' extension instead. (This also includes files ending with a dot, which is possible in linux)

• Output should be sorted by extension using string (lexical) order.

• When no parameter is supplied the following should be displayed:

   :::text
   usage: ext_info.py path
   displays number of files and total size of files per extension in the specified path.
  

• (This exercise scope is standard library modules, and not 3rd party packages)

Recommended modules and functions:

• sys.argv

  The list of command line arguments passed to a Python script. argv[0] is the script name...

  Example:

   #!python
   import sys
   if __name__ == '__main__':
       print("I am:", sys.argv[0])
       for i, s in enumerate(sys.argv[1:]):
           print "Parameter #{}: {}".format(i+1, s)
  

• os.listdir:

  Return a list containing the names of the entries in the directory given by path...

  Example:

   :::python
   import os
  
   for filename in os.listdir('.'):
       print filename
  

• os.path.join. Always use this to concatenate paths.

  Join one or more path components intelligently...

  Windows example:

   :::python
   import os.path
  
   home_folder = r'c:\users\foo'
   child = r'projects'
   filename = r'pictures\baz.jpeg'
  
   print os.path.join(home_folder, child, filename)
   # prints: c:\users\foo\projects\pictures\baz.jpeg
  

  Linux example:

   :::python
   import os.path
  
   home_folder = '/home/foo/'
   child = 'projects'
   filename = 'pictures/baz.jpeg'
  
   print os.path.join(home_folder, child, filename)
   # prints: /home/foo/projects/pictures/baz.jpeg
  

• And: os.path.isdir, os.path.getsize, and os.path.splitext.

• Bonus: use collection.defaultdict.

  Example:

   #!python
   from collections import defaultdict
  
   def create_player():
       return {
           'hit points': 10,
           'money': 1000,
       }
  
   players = defaultdict(create_player)
  
   # defaultdict calls create_player on first access to players['foo'].
   # There is no need to explicitly call:
   #   players['foo'] = create_player()
  
   players['Aragorn']['hit points'] += 5
   players['Frodo']['hit points'] -= 1
   players['Bilbo']['money'] += 50
  
   for name, info in players.items():
       print name, info