Python 2 Dimension Array (Matrix) with string indices

Question

In Python (2.7), is there a native 2 dimensional data structure that can be accessed through string based indices?

I know you can have a dictionary that can be accessed with a string index, for example:

>>> dic = dict()
>>> dic['grumpy'] = 'cat'
>>> print(dict['grumpy'])
'cat'

But what I would like is a data structure that can be accessed like:

>>> dic['grumpy']['frumpy'] = 'cat'
>>> print(dict['grumpy']['frumpy'])
'cat'

Array seems to be a no-go since it only allows integer based access... any suggestions? Thanks!

Martijn Pieters · Accepted Answer · 2013-01-17 16:13:31Z

9

Use a defaultdict:

from collections import defaultdict

nesteddict = defaultdict(dict)

nesteddict['abc']['spam'] = 'ham'

Note that what you describe is a simple nested structure; you can also build it without using defaultdict but that class makes it all the easier to do so.

answered Jan 17, 2013 at 16:13

Martijn Pieters

1.1m326 gold badges4.2k silver badges3.4k bronze badges

Sign up to request clarification or add additional context in comments.

9 Comments

DSM Over a year ago

Oh, come on. That's just not fair. Promise me that when you hit 100k you'll give the rest of us at least thirty seconds worth of handicap!

ToOsIK Over a year ago

Amazing! thank you sir for the extremely fast response!... I'll accept the answer once the minimum 15 mins have passed. :)

Martijn Pieters Over a year ago

@ToOsIK: I am in to hurry; perhaps others can think of something that is better still, give them a chance too! :-)

Martijn Pieters Over a year ago

@DSM: I'll be gone a large part of tomorrow... try and spot the lulls! :-P

mgilson Over a year ago

@DSM -- Do you think we could convince the moderators that Martijn has somehow hacked SO so that he gets the chance to see every question before other users -- Or that he's some kind of really smart and useful non-spam-bot? (Seriously -- I don't think I can even type that quickly)

|

Collectives™ on Stack Overflow

Python 2 Dimension Array (Matrix) with string indices

1 Answer 1

9 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

9 Comments

Your Answer

Sign up or log in

Post as a guest

Related