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Forked from ChunMinChang/remove_c_style_comments.py
Last active January 5, 2021 12:36
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Python: Remove C/C++ style comments #parser
#!/usr/bin/python
import re
import sys
import os.path
# Method 1: As described by saltycrane (https://www.saltycrane.com/blog/2007/11/remove-c-comments-python/):
# This regular expression was created by Jeffrey Friedl and later modified by Fred Curtis.
# Check the above link for details.
def removeComments(text):
""" remove c-style comments.
text: blob of text with comments (can include newlines)
returns: text with comments removed
"""
pattern = r"""
## --------- COMMENT ---------
//.*?$ ## Start of // .... comment
| ##
/\* ## Start of /* ... */ comment
[^*]*\*+ ## Non-* followed by 1-or-more *'s
( ##
[^/*][^*]*\*+ ##
)* ## 0-or-more things which don't start with /
## but do end with '*'
/ ## End of /* ... */ comment
| ## -OR- various things which aren't comments:
( ##
## ------ " ... " STRING ------
" ## Start of " ... " string
( ##
\\. ## Escaped char
| ## -OR-
[^"\\] ## Non "\ characters
)* ##
" ## End of " ... " string
| ## -OR-
##
## ------ ' ... ' STRING ------
' ## Start of ' ... ' string
( ##
\\. ## Escaped char
| ## -OR-
[^'\\] ## Non '\ characters
)* ##
' ## End of ' ... ' string
| ## -OR-
##
## ------ ANYTHING ELSE -------
. ## Anything other char
[^/"'\\]* ## Chars which doesn't start a comment, string
) ## or escape
"""
regex = re.compile(pattern, re.VERBOSE|re.MULTILINE|re.DOTALL)
noncomments = [m.group(2) for m in regex.finditer(text) if m.group(2)]
return "".join(noncomments)
# Method 2: Answered by Markus Jarderot on stackoverflow
# Link: https://stackoverflow.com/questions/241327/remove-c-and-c-comments-using-python
def commentRemover(text):
def replacer(match):
s = match.group(0)
if s.startswith('/'):
return " " # note: a space and not an empty string
else:
return s
pattern = re.compile(
r'//.*?$|/\*.*?\*/|\'(?:\\.|[^\\\'])*\'|"(?:\\.|[^\\"])*"',
re.DOTALL | re.MULTILINE
)
return re.sub(pattern, replacer, text)
# Combine multiple blank lines into one empty line
# Added by Technblogy.com
def blankLineRemover(text):
def replacer(match):
s = match.group(0)
return ""
pattern = re.compile(
r'^\s*$',
re.DOTALL | re.MULTILINE
)
return re.sub(pattern, replacer, text)
filenames = ['test.h']
for filename in filenames:
with open(filename) as f:
# use removeComments or commentRemover, two methods
# uncmtFile = removeComments(f.read())
uncmtFile = commentRemover(f.read())
# blankLineRemover combines multiple blank lines into one empty line
uncmtFile = blankLineRemover(uncmtFile)
with open(os.path.splitext(filename)[0]+'.nocmt'+os.path.splitext(filename)[1], "w") as new_file:
new_file.write(uncmtFile)
/* This is a C-style comment. */
This is not a comment.
/* This is another
* C-style comment.
*/
"This is /* also not a comment */"
// This is also a comment
This is still // a comment
//blank lines
This is still /* a comment */
//blank comments
//blank comments
This is still /* a comment */ again
This is the final line
@Technblogy
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Author

remove_c_style_comments.py of test.h:

This is not a comment.

"This is /* also not a comment */"

This is still  

This is still  

This is still   again
This is the final line

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