autovivification

What's the best way to initialize a dict of dicts in Python? Question: A lot of times in Perl, I’ll do something like this: $myhash{foo}{bar}{baz} = 1 How would I translate this to Python? So far I have: if not ‘foo’ in myhash: myhash[‘foo’] = {} if not ‘bar’ in myhash[‘foo’]: myhash[‘foo’][‘bar’] = {} myhash[‘foo’][‘bar’][‘baz’] …

What is the best way to implement nested dictionaries? Question: I have a data structure which essentially amounts to a nested dictionary. Let’s say it looks like this: {‘new jersey’: {‘mercer county’: {‘plumbers’: 3, ‘programmers’: 81}, ‘middlesex county’: {‘programmers’: 81, ‘salesmen’: 62}}, ‘new york’: {‘queens county’: {‘plumbers’: 9, ‘salesmen’: 36}}} Now, maintaining and creating this …