Recursively formatting a dictionary of strings

I have a use-case where I'm using a dictionary as a basis for generating a configuration file, and many of the values in the file share pieces, such as URL bases or credentials. I will also be generating configuration files for several different instances from the same dictionary.

I wanted a simple way to define replaceable parts of the dictionary. I made a couple of Google searches, didn't find anything on the first page, so I wrote this:

	def dict_format(original, **kwargs):
	"""Recursively format the values in *original* with *kwargs*.
	>>> sample = {"key": "{value}", "sub-dict": {"sub-key": "sub-{value}"}}
	>>> dict_format(sample, value="Bob") == \
	{'key': 'Bob', 'sub-dict': {'sub-key': 'sub-Bob'}}
	True
	"""
	new = {}
	for key, value in original.items():
	if type(value) == type({}):
	new[key] = dict_format(value, **kwargs)
	elif type(value) == type(""):
	new[key] = value.format(**kwargs)
	else:
	new[key] = value
	return new

view raw dict_format.py hosted with ❤ by GitHub

gist for dict_format.py

I hope it's useful to someone else, or that I find it next time I have this use-case. :)