read plain configuration files (without ini sections) using ConfigParser into dictionaries (so we can easily change valies), then built a string to write to file

read_plain_configs.py

import ConfigParser
from collections import OrderedDict

class NoSectionConfig(object):
    section = "dummy"
    def __init__(self, fp):
        self.fp = fp
        self.section_head = "[{0}]\n".format(self.section)

    def readline(self):
        if self.section_head:
            try:
                return self.section_head
            finally:
                self.section_head = None
        else:
            return self.fp.readline()

cfg = ConfigParser.SafeConfigParser()
with open('main.cf', 'r') as f:
    cfg.readfp(NoSectionConfig(f))

# config -> dict
data = OrderedDict(cfg.items(NoSectionConfig.section))

# dict -> string
s = []
for k,v in data.items():
    s.append("{0} = {1}".format(k, v))
print("\n".join(s))