Iterating through directories with Python

Question

I need to iterate through the subdirectories of a given directory and search for files  If I get a file I have to open it and change the content and replace it with my own lines   I tried this   import os  rootdir   C  Users sid Desktop test   for subdir  dirs  files in os walk rootdir       for file in files          f open file  r           lines f readlines           f close           f open file  w           for line in lines              newline    No you are not              f write newline          f close     but I am getting an error  What am I doing wrong

User · Answer

From python  gt   3 5 onward  you can use     glob iglob path     recursive True  and it seems the most pythonic solution  i e   import glob  os  for filename in glob iglob   pardadox-music      recursive True       if os path isfile filename     filter dirs         print filename   Output   pardadox-music modules her1 mod  pardadox-music modules her2 mod       Notes  1 - glob iglob  glob iglob pathname  recursive False  Return an iterator which yields the same values as glob   without actually storing them all simultaneously   2 - If recursive is True  the pattern      will match any files and zero or more directories and subdirectories  3 - If the directory contains files starting with    they won   t be matched by default  For example  consider a directory containing  card gif  and  card gif   gt  gt  gt  import glob  gt  gt  gt  glob glob    gif     card gif     gt  gt  gt  glob glob   c      card gif    4 - You can also use rglob pattern   which is the same as calling  glob    with     added in front of the given relative  pattern

User · Answer

The actual walk through the directories works as you have coded it  If you replace the contents of the inner loop with a simple print statement you can see that each file is found   import os rootdir    C  Users sid Desktop test   for subdir  dirs  files in os walk rootdir       for file in files          print os path join subdir  file    If you still get errors when running the above  please provide the error message     Updated for Python3  import os rootdir    C  Users sid Desktop test   for subdir  dirs  files in os walk rootdir       for file in files          print os path join subdir  file

User · Answer

Another way of returning all files in subdirectories is to use the pathlib module  introduced in Python 3 4  which provides an object oriented approach to handling filesystem paths  Pathlib is also available on Python 2 7 via the pathlib2 module on PyPi   from pathlib import Path  rootdir   Path  C  Users sid Desktop test     Return a list of regular files only  not directories file list    f for f in rootdir glob         if f is file       For absolute paths instead of relative the current dir file list    f for f in rootdir resolve   glob         if f is file     Since Python 3 5  the glob module also supports recursive file finding  import os from glob import iglob  rootdir glob    C  Users sid Desktop test         Note the added asterisks   This will return absolute paths file list    f for f in iglob rootdir glob  recursive True  if os path isfile f    The file list from either of the above approaches can be iterated over without the need for a nested loop  for f in file list      print f    Replace with desired operations

[python] Iterating through directories with Python

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