Using ConfigParser to read a file without section name

Alex Martelli provided a solution for using ConfigParser to parse .properties files (which are apparently section-less config files).

His solution is a file-like wrapper that will automagically insert a dummy section heading to satisfy ConfigParser's requirements.

You can do this in a single line of code.

In python 3, prepend a fake section header to your config file data, and pass it to read_string().

from configparser import ConfigParser

parser = ConfigParser()
with open("foo.conf") as stream:
    parser.read_string("[top]\n" + stream.read())  # This line does the trick.

You could also use itertools.chain() to simulate a section header for read_file(). This might be more memory-efficient than the above approach, which might be helpful if you have large config files in a constrained runtime environment.

from configparser import ConfigParser
from itertools import chain

parser = ConfigParser()
with open("foo.conf") as lines:
    lines = chain(("[top]",), lines)  # This line does the trick.
    parser.read_file(lines)

In python 2, prepend a fake section header to your config file data, wrap the result in a StringIO object, and pass it to readfp().

from ConfigParser import ConfigParser
from StringIO import StringIO

parser = ConfigParser()
with open("foo.conf") as stream:
    stream = StringIO("[top]\n" + stream.read())  # This line does the trick.
    parser.readfp(stream)

With any of these approaches, your config settings will be available in parser.items('top').

You could use StringIO in python 3 as well, perhaps for compatibility with both old and new python interpreters, but note that it now lives in the io package and readfp() is now deprecated.

Alternatively, you might consider using a TOML parser instead of ConfigParser.