Python - ConfigParser throwing comments

Question

Based on ConfigParser module how can I filter out and throw every comments from an ini file?

import ConfigParser
config = ConfigParser.ConfigParser()
config.read("sample.cfg")

for section in config.sections():
    print section
    for option in config.options(section):
        print option, "=", config.get(section, option)

eg. in the ini file below the above basic script prints out the further comments lines as well like:

something  = 128     ; comment line1
                      ; further comments 
                       ; one more line comment

What I need is having only the section names and pure key-value pairs inside them without any comments. Does ConfigParser handles this somehow or should I use regexp...or? Cheers

What does "throw out" mean? Please provide a clear statement of what you're really trying to do -- why do you need to "throw out" data from a file? Where does it go? What's left behind? — S.Lott, Feb 19 '09 at 12:08

SilentGhost · Answer 1 · 2009-02-19T12:28:59.263

according to docs lines starting with ; or # will be ignored. it doesn't seem like your format satisfies that requirement. can you by any chance change format of your input file?

edit: since you cannot modify your input files, I'd suggest pre-parsing them with something along the lines:

tmp_fname = 'config.tmp'
with open(config_file) as old_file:
    with open(tmp_fname, 'w') as tmp_file:
        tmp_file.writelines(i.replace(';', '\n;') for i in old_lines.readlines())
# then use tmp_fname with ConfigParser

obviously if semi-colon is present in options you'll have to be more creative.

score 3 · Answer 2 · answered Feb 19 '09 at 13:38

3

Best way is to write a commentless file subclass:

class CommentlessFile(file):
    def readline(self):
        line = super(CommentlessFile, self).readline()
        if line:
            line = line.split(';', 1)[0].strip()
            return line + '\n'
        else:
            return ''

You could use it then with configparser (your code):

import ConfigParser
config = ConfigParser.ConfigParser()
config.readfp(CommentlessFile("sample.cfg"))

for section in config.sections():
    print section
    for option in config.options(section):
        print option, "=", config.get(section, option)

answered Feb 19 '09 at 13:38

nosklo

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I think there's a small typo there, it should be super(CommentlessFile, self).readline(), instead of CommentRemover. – sykora Feb 19 '09 at 13:42
@sykora: I fixed that 5 seconds after the first post :) – nosklo Feb 19 '09 at 14:49

score 2 · Answer 3 · answered Apr 20 '12 at 06:30

Python 3 comes with a build-in solution: The class configparser.RawConfigParser has constructor argument inline_comment_prefixes. Example:

class MyConfigParser(configparser.RawConfigParser):
    def __init__(self):
      configparser.RawConfigParser.__init__(self, inline_comment_prefixes=('#', ';'))

score 2 · Answer 4 · answered Feb 19 '09 at 11:40

2

It seems your comments are not on lines that start with the comment leader. It should work if the comment leader is the first character on the line.

answered Feb 19 '09 at 11:40

sykora

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Thanks, but unfortunately I am not allowed to modify the input ini file.In this format of ini file as I noticed all the comment lines are appended to the value part of last key - except the first comment line (right after value) which is dropped indeed. – Feb 19 '09 at 11:53
In fact my task is to compare two ini files (every significant part except comments) – Feb 19 '09 at 11:54
Then you'll probably have to create a temporary file and/or use ConfigParser.readfp() to scrap the comments. – sykora Feb 19 '09 at 12:01

score 1 · Answer 5 · answered Jan 12 '11 at 05:37

1

As the doc said: "(For backwards compatibility, only ; starts an inline comment, while # does not.)" So use ";" and not "#" for inline comments. It is working well for me.

answered Jan 12 '11 at 05:37

Pierre Thibault

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Python - ConfigParser throwing comments

5 Answers5