How can I iterate over files in a given directory

Question

I need to iterate through all  asm files inside a given directory and do some actions on them    How can this be done in a efficient way

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Original answer  import os  for filename in os listdir directory       if filename endswith  quot  asm quot   or filename endswith  quot  py quot                print os path join directory  filename           continue     else          continue  Python 3 6 version of the above answer  using os - assuming that you have the directory path as a str object in a variable called directory in str  import os  directory   os fsencode directory in str       for file in os listdir directory        filename   os fsdecode file       if filename endswith  quot  asm quot   or filename endswith  quot  py quot                print os path join directory  filename            continue      else           continue  Or recursively  using pathlib  from pathlib import Path  pathlist   Path directory in str  glob       asm   for path in pathlist         because path is object not string      path in str   str path         print path in str    Use rglob to replace glob       asm   with rglob    asm    This is like calling Path glob   with       added in front of the given relative pattern     from pathlib import Path  pathlist   Path directory in str  rglob    asm   for path in pathlist         because path is object not string      path in str   str path         print path in str

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I m not quite happy with this implementation yet  I wanted to have a custom constructor that does DirectoryIndex  make next os walk input path    such that you can just pass the path you want a file listing for  Edits welcome   import collections import os  DirectoryIndex   collections namedtuple  DirectoryIndex     root    dirs    files     for file name in DirectoryIndex  next os walk        files      file path   os path join path  file name

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I really like using the scandir directive that is built into the os library  Here is a working example   import os  i   0 with os scandir   usr local bin   as root dir      for path in root dir          if path is file                i    1             print f Full path is   path  and just the name is   path name    print f  i  files scanned successfully

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This will iterate over all descendant files  not just the immediate children of the directory   import os  for subdir  dirs  files in os walk rootdir       for file in files           print os path join subdir  file          filepath   subdir   os sep   file          if filepath endswith   asm                print  filepath

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Since Python 3 5  things are much easier with os scandir    with os scandir path  as it      for entry in it          if entry name endswith   asm   and entry is file                print entry name  entry path       Using scandir   instead of listdir   can significantly increase the   performance of code that also needs file type or file attribute   information  because os DirEntry objects expose this information if   the operating system provides it when scanning a directory  All   os DirEntry methods may perform a system call  but is dir   and   is file   usually only require a system call for symbolic links    os DirEntry stat   always requires a system call on Unix but only   requires one for symbolic links on Windows

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You can try using glob module   import glob  for filepath in glob iglob  my dir   asm        print filepath    and since Python 3 5 you can search subdirectories as well   glob glob       txt   recursive True      gt    2 txt    sub 3 txt     From the docs      The glob module finds all the pathnames matching a specified pattern according to the rules used by the Unix shell  although results are returned in arbitrary order  No tilde expansion is done  but       and character ranges expressed with    will be correctly matched

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Here s how I iterate through files in Python    import os  path    the name of your path   folder   os fsencode path   filenames       for file in os listdir folder       filename   os fsdecode file      if filename endswith     jpeg     png     gif        whatever file types you re using            filenames append filename   filenames sort     now you have the filenames and can do something with them   NONE OF THESE TECHNIQUES GUARANTEE ANY ITERATION ORDERING    Yup  super unpredictable  Notice that I sort the filenames  which is important if the order of the files matters  i e  for video frames or time dependent data collection  Be sure to put indices in your filenames though

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You can use glob for referring the directory and the list     import glob import os   to get the current working directory name cwd   os getcwd    Load the images from images folder  for f in glob glob  images   jpg           dir name   get dir name f      image file name   dir name     jpg       To print the file name with path  path will be in string      print  image file name    To get the list of all directory in array you can use os    os listdir directory

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Python 3 4 and later offer pathlib in the standard library  You could do   from pathlib import Path  asm pths    pth for pth in Path cwd   iterdir               if pth suffix      asm     Or if you don t like list comprehensions   asm paths      for pth in Path cwd   iterdir        if pth suffix      asm           asm pths append pth    Path objects can easily be converted to strings

[python] How can I iterate over files in a given directory?

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