Preserve case in ConfigParser?

Question

I have tried to use Python\'s ConfigParser module to save settings. For my app it\'s important that I preserve the case of each name in my sections. The docs mention that pa

Answer 1

I know this question is answered, but I thought some people might find this solution useful. This is a class that can easily replace the existing ConfigParser class.

Edited to incorporate @OozeMeister's suggestion:

class CaseConfigParser(ConfigParser):
    def optionxform(self, optionstr):
        return optionstr

Usage is the same as normal ConfigParser.

parser = CaseConfigParser()
parser.read(something)

This is so you avoid having to set optionxform every time you make a new ConfigParser, which is kind of tedious.

Answer 2

Add to your code:

config.optionxform = lambda option: option  # preserve case for letters

Answer 3

For me worked to set optionxform immediately after creating the object

config = ConfigParser.RawConfigParser()
config.optionxform = str 

Answer 4

The documentation is confusing. What they mean is this:

import ConfigParser, os
def get_config():
    config = ConfigParser.ConfigParser()
    config.optionxform=str
    try:
        config.read(os.path.expanduser('~/.myrc'))
        return config
    except Exception, e:
        log.error(e)

c = get_config()  
print c.options('rules')

I.e. override optionxform, instead of calling it; overriding can be done in a subclass or in the instance. When overriding, set it to a function (rather than the result of calling a function).

I have now reported this as a bug, and it has since been fixed.

Answer 5

Caveat:

If you use defaults with ConfigParser, i.e.:

config = ConfigParser.SafeConfigParser({'FOO_BAZ': 'bar'})

and then try to make the parser case-sensitive by using this:

config.optionxform = str

all your options from config file(s) will keep their case, but FOO_BAZ will be converted to lowercase.

To have defaults also keep their case, use subclassing like in @icedtrees answer:

class CaseConfigParser(ConfigParser.SafeConfigParser):
    def optionxform(self, optionstr):
        return optionstr

config = CaseConfigParser({'FOO_BAZ': 'bar'})

Now FOO_BAZ will keep it's case and you won't have InterpolationMissingOptionError.