Python: Traverse Directory

By Xah Lee. Date: . Last updated: .

Suppose you want to visit every file in a directory. For example, do find/replace on all HTML files. You can use os.path.walk().

Note: os.path.walk() is deprecated, and removed in Python 3. You should use os.walk() instead, also available in python 2.7.x. For how-to, see:

Python 3: Traverse Directory

# -*- coding: utf-8 -*-
# python 2

# traverse a directory

import os

mydir= "/home/xyz/Documents"

def myfun(s1, s2, s3):
    print "s1 is {}".format(s1)
    print "s2 is {}".format(s2)
    print "s3 is {}".format(s3)
    print "--------------------------"

os.path.walk(mydir, myfun, "xyz")

os.path.walk(base_dir, f, arg) will walk a dir starting at base_dir. When it sees a directory (including base_dir), it will call f(arg, current_dir , list_of_children).

where:

Here's a example of filter some files by file name extension, and for each file we want, call a function on it.

# -*- coding: utf-8 -*-
# python 2

# traverse a dir, and list only html files

import os

mydir= "/home/xyz/Documents/"

def processThisFile(fpath):
    print "g touched:", fpath

def filterFile(dummy, thisDir, dirChildrenList):
    for child in dirChildrenList:
        if ".html" == os.path.splitext(child)[1] and os.path.isfile(thisDir+"/"+child):
            processThisFile(thisDir+"/"+child)

os.path.walk(mydir, filterFile, None)

Note that os.path.splitext() splits a string into two parts, a portion before the last period, and the rest in the second portion. Effectively it is used for getting file suffix. The os.path.isfile() makes sure that this is a actual file and not a dir with “.html” suffix.

Note: before Python 2.4.2: the first arg to os.path.walk must not end in a slash.

for Python 3, see: Python 3: Traverse Directory

Python Text Processing

  1. Read/Write File
  2. Walk Directory
  3. File Path
  4. Process Unicode
  5. Convert File Encoding
  6. Convert File Encoding in a Dir
  7. Find Replace in dir
  8. Find Replace by Regex
  9. Count Word Frequency

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Python

  1. Python 3 Basics
  2. Python 2 Basics
  3. Python 2 and 3 Difference
  4. Print Version
  5. Builtin Help
  6. Quote String
  7. String Methods
  8. Format String
  9. Operators
  10. Complex Numbers
  11. True, False
  12. if then else
  13. Loop
  14. List Basics
  15. Loop Thru List
  16. Map f to List
  17. Copy Nested List
  18. List Comprehension
  19. List Methods
  20. Sort
  21. Dictionary
  22. Loop Thru Dict
  23. Dict Methods
  24. Tuple
  25. Sets
  26. Function
  27. Closure
  28. 2 Closure
  29. Decorator
  30. Class
  31. Object, ID, Type
  32. List Modules
  33. Write a Module
  34. Unicode 🐍

Regex

  1. Regex Basics
  2. Regex Reference

Text Processing

  1. Read/Write File
  2. Traverse Directory
  3. File Path
  4. Process Unicode
  5. Convert File Encoding
  6. Find Replace in dir
  7. Find Replace by Regex
  8. Count Word Frequency

Web

  1. Send Email
  2. GET Web Page
  3. Web Crawler
  4. HTTP POST

Misc

  1. JSON
  2. Find Script Path
  3. Get Env Var
  4. System Call
  5. Decompress Gzip
  6. Append String in Loop
  7. Timing f timeit
  8. Keyword Arg Default Value Unstable
  9. Check Page Load Size
  10. Thumbnail Generation