Creating a dictionary with same values [duplicate]

Question

Suppose I have dictionary a = {} and I want to have it a result like this

value = 12
a = {'a':value,'b':value,'f':value,'h':value,'p':value}

and so on for many keys:same value. Now of course I can do it like this

a.update({'a':value})
a.update({'b':value})

and so on.... but since the value is same for all the keys, don't we have a more pythonic approach to do this?

Answer 1

You could use dict comprehensions (python 2.7+):

>>> v = 12
>>> d = {k:v for k in 'abfhp'}
>>> print d
{'a': 12, 'h': 12, 'b': 12, 'p': 12, 'f': 12}

Answer 2

How about creating a new dictionary with the keys that you want and a default value?. Check the fromkeys method.

>>> value=12
>>> a=dict.fromkeys(['a', 'b', 'f', 'h', 'p'], value)
>>> print a
{'a': 12, 'h': 12, 'b': 12, 'p': 12, 'f': 12}