Lists in ConfigParser

Question

The typical ConfigParser generated file looks like:

[Section]
bar=foo
[Section 2]
bar2= baz

Now, is there a way to index lists like, for in

Answer 1

Also a bit late, but maybe helpful for some. I am using a combination of ConfigParser and JSON:

[Foo]
fibs: [1,1,2,3,5,8,13]

just read it with:

>>> json.loads(config.get("Foo","fibs"))
[1, 1, 2, 3, 5, 8, 13]

You can even break lines if your list is long (thanks @peter-smit):

[Bar]
files_to_check = [
     "/path/to/file1",
     "/path/to/file2",
     "/path/to/another file with space in the name"
     ]

Of course i could just use JSON, but i find config files much more readable, and the [DEFAULT] Section very handy.

Answer 2

No mention of the converters kwarg for ConfigParser() in any of these answers was rather disappointing.

According to the documentation you can pass a dictionary to ConfigParser that will add a get method for both the parser and section proxies. So for a list:

example.ini

[Germ]
germs: a,list,of,names, and,1,2, 3,numbers

Parser example:

cp = ConfigParser(converters={'list': lambda x: [i.strip() for i in x.split(',')]})
cp.read('example.ini')
cp.getlist('Germ', 'germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']
cp['Germ'].getlist('germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']

This is my personal favorite as no subclassing is necessary and I don't have to rely on an end user to perfectly write JSON or a list that can be interpreted by ast.literal_eval.

Answer 3

So another way, which I prefer, is to just split the values, for example:

#/path/to/config.cfg
[Numbers]
first_row = 1,2,4,8,12,24,36,48

Could be loaded like this into a list of strings or integers, as follows:

import configparser

config = configparser.ConfigParser()
config.read('/path/to/config.cfg')

# Load into a list of strings
first_row_strings = config.get('Numbers', 'first_row').split(',')

# Load into a list of integers
first_row_integers = [int(x) for x in config.get('Numbers', 'first_row').split(',')]

This method prevents you from needing to wrap your values in brackets to load as JSON.