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).


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):

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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  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
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  29. Decorator
  30. Class
  31. Object, ID, Type
  32. List Modules
  33. Write a Module
  34. Unicode 🐍


  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


  1. Send Email
  2. GET Web Page
  3. Web Crawler


  1. JSON
  2. Find Script Path
  3. Get Env Var
  4. System Call
  5. Decompress Gzip
  6. Append String in Loop
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  8. Keyword Arg Default Value Unstable
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