CODEWITHSUNDEEP
pythondictionary
Bruno A
Bruno A

Reputation: 127

Dictionary with tuples as values

Is it possible to create a dictionary like this in Python?

{'string':[(a,b),(c,d),(e,f)], 'string2':[(a,b),(z,x)...]}

The first error was solved, thanks! But, i'm doing tuples in a for loop, so it changes all the time. When i try to do:

d[key].append(c)

As c being a tuple.

I am getting another error now:

AttributeError: 'tuple' object has no attribute 'append'

Thanks for all the answers, i managed to get it working properly!

Upvotes: 0

Views: 1997

Answers (1)

Sajjan Singh
Sajjan Singh

Reputation: 2553

Is there a reason you need to construct the dictionary in that fashion? You could simply define

d = {'string': [('a', 'b'), ('c', 'd'), ('e', 'f')], 'string2': [('a', 'b'), ('z', 'x')]}

And if you wanted a new entry:

d['string3'] = [('a', 'b'), ('k', 'l')]

And if you wish to append tuples to one of your lists:

d['string2'].append(('e', 'f'))

Now that your question is clearer, to simply construct a dictionary with a loop, assuming you know the keys beforehand in some list keys:

d = {}

for k in keys:
    d[k] = []

    # Now you can append your tuples if you know them.  For instance:
    # d[k].append(('a', 'b'))

There is also a dictionary comprehension if you simply want to build the dictionary first:

d = {k: [] for k in keys}

Thanks for the answer. But, is there any way to do this using defaultdict?

from collections import defaultdict

d = defaultdict(list)

for i in 'string1','string2':
   d[i].append(('a','b'))

Or you can use setdefault:

 d = {}
 for i in 'string1','string2':
     d.setdefault(i, []).append(('a','b'))

Upvotes: 2

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