How To Write Ini-files Without Sections?

I need to create a file in the following format: option1 = 99 option2 = 34 do_it = True ... When I use ConfigParser, I have to put all my data into a section with an artificial na

Solution 1:

[NB: the following is written for Python 3; you would need to make a couple of minor changes to make it run under Python 2.]

Maybe something like this; here, I write to an io.StringIO object in memory, then take everything but the first line and write that out to the target file.

import configparser
import io


buf = io.StringIO()

ini_writer = configparser.ConfigParser()
ini_writer.set('DEFAULT', 'option1', '99')
ini_writer.set('DEFAULT', 'option2', '34')
ini_writer.set('DEFAULT', 'do_it', 'True')
ini_writer.write(buf)

buf.seek(0)
next(buf)
withopen('my.ini', 'w') as fd:
    fd.write(buf.read())

By using the section name DEFAULT we avoid having to create a new section first.

This results in:

$ cat my.ini
option1 = 99
option2 = 34
do_it = True

Solution 2:

As ConfigParser doesn't support this I personally would probably opt to monkeypatch the write method to support non-section writing.

from configparser import ConfigParser


def_write_section_custom(self, fp, section_name, section_items, delimiter):
    for key, value in section_items:
        value = self._interpolation.before_write(self, section_name, key, value)
        if value isnotNoneornot self._allow_no_value:
            value = delimiter + str(value).replace('\n', '\n\t')
        else:
            value = ''
        fp.write('{}{}\n'.format(key, value))
    fp.write('\n')


ini_writer = ConfigParser()
ConfigParser._write_section = _write_section_custom
ini_writer.add_section('SECTION')
ini_writer.set('SECTION', 'option1', '99')
ini_writer.set('SECTION', 'option2', '34')
ini_writer.set('SECTION', 'do_it', 'True')
withopen('my.ini', 'w') as f:
    ini_writer.write(f)

With that I get:

$ cat my.ini 
option1 = 99
option2 = 34
do_it = True

I've tested this under Python 3.8 so you would need to test/adjust for 2.7. Also bear in mind that the reading of the custom ini would need to be adapted/monkeypatched. You could also wrap this into a custom ConfigParser class of your own so that you have it reusable wherever you need it in your project.