How to set default value to all keys of a dict object in python?

Question

I know you can use setdefault(key, value) to set default value for a given key, but is there a way to set default values of all keys to some value after creating a dict ?

Answer 1

Is this what you want:

>>> d={'a':1,'b':2,'c':3}
>>> default_val=99
>>> for k in d:
...     d[k]=default_val
...     
>>> d
{'a': 99, 'b': 99, 'c': 99}
>>> 

>>> d={'a':1,'b':2,'c':3}
>>> from collections import defaultdict
>>> d=defaultdict(lambda:99,d)
>>> d
defaultdict( at 0x03D21630>, {'a': 1, 'c': 3, 'b': 2})
>>> d[3]
99