def dict_merge(dct, merge_dct):
for key in merge_dct.keys():<EOL><INDENT>if (<EOL>key in dct<EOL>and isinstance(dct[key], dict)<EOL>and isinstance(merge_dct[key], collections.Mapping)<EOL>):<EOL><INDENT>dict_merge(dct[key], merge_dct[key])<EOL><DEDENT>else:<EOL><INDENT>dct[key] = merge_dct[key]<EOL><DEDENT><DEDENT>
Recursive dict merge. Inspired by :meth:``dict.update()``, instead of
    updating only top-level keys, dict_merge recurses down into dicts nested
    to an arbitrary depth, updating keys. The ``merge_dct`` is merged into
    ``dct``.
    :param dct: dict onto which the merge is executed
    :param merge_dct: dct merged into dct
    :return: None