Update INI file without removing comments

Question

Consider the following INI file:

[TestSettings] # First comment goes here environment = test  [Browser] # Second comment goes here browser = chrome chromedriver = default  ... 

I'm using Python 2.7 to update the ini file:

config = ConfigParser.ConfigParser() config.read(path_to_ini) config.set('TestSettings','environment',r'some_other_value')  with open(path_to_ini, 'wb') as configfile:     config.write(configfile) 

How can I update the INI file without removing the comments. The INI file is updated but the comments are removed.

[TestSettings] environment = some_other_value  [Browser] browser = chrome chromedriver = default 

Answer 1

The reason that comments in config files are wiped when writing back is that the write method didn't take care of comments at all. It just writes key/value pairs.

The easiest way to bypass this is to init configparser object with a customized comment prefix and allow_no_value = True. If we want to keep the default "#" and ";" comment lines in the file, we can use comment_prefixes='/'.

i.e., to keep comments, you have to trick configparser into believing this is not a comment, this line is a key without a value. Interesting :)

# set comment_prefixes to a string which you will not use in the config file config = configparser.ConfigParser(comment_prefixes='/', allow_no_value=True) config.read_file(open('example.ini')) ... config.write(open('example.ini', 'w'))