SaltyCrane Blog

Notes on Python, Django, and web development on Ubuntu Linux

How to remove ^M characters from a file with Python

Date: Oct. 3, 2011 | Tags: files_directories, python | 4 Comments

Use the following Python script to remove ^M (carriage return) characters from your file and replace them with newline characters only. To do this in Emacs, see my notes here.

remove_ctrl_m_chars.py:

import os
import sys
import tempfile


def main():
    filename = sys.argv[1]
    with tempfile.NamedTemporaryFile(delete=False) as fh:
        for line in open(filename):
            line = line.rstrip()
            fh.write(line + '\n')
        os.rename(filename, filename + '.bak')
        os.rename(fh.name, filename)


if __name__ == '__main__':
    main()

Run it

$ python remove_ctrl_m_chars.py myfile.txt

Documentation

How to get the filename and it's parent directory in Python — posted 2011-12-28
Options for listing the files in a directory with Python — posted 2010-04-19
Monitoring a filesystem with Python and Pyinotify — posted 2010-04-09
os.path.relpath() source code for Python 2.5 — posted 2010-03-31
A hack to copy files between two remote hosts using Python — posted 2010-02-08

4 Comments — Comments feed for this post

#1 Harsh commented on 2011-11-23:

Why would you need this as a utility when you have dos2unix, whose entire purpose is for this?

#2 Eliot commented on 2011-11-23:

Harsh: Because I have a bad case of NIH and because I wasn't familiar with dos2unix. Thanks for the tip; I'll use dos2unix next time.

#3 Kaixi commented on 2011-12-04:

Wonderful little script :)

#4 Khalil commented on 2011-12-30:

or use vi editor's command

:%s/r//g

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