setting the default string value of Python's collections.defaultdict
The argument to defaultdict is a function (or rather, a callable object) that returns the default value. So you can pass in a lambda that returns your desired default.
>>> from collections import defaultdict>>> d = defaultdict(lambda: 'My default')>>> d['junk']'My default'Edited to explain lambda:
lambda is just a shorthand for defining a function without giving it a name. You could do the same with an explicit def:
>>> def myDefault():... return 'My default'>>>> d = defaultdict(myDefault)>>> d['junk']'My default'See the documentation for more info.