Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?

Question

For example I have two dicts:

Dict A: {\'a\': 1, \'b\': 2, \'c\': 3}
Dict B: {\'b\': 3, \'c\': 4, \'d\': 5}

I need a pythonic way of \'comb

Answer 1

The one with no extra imports!

Their is a pythonic standard called EAFP(Easier to Ask for Forgiveness than Permission). Below code is based on that python standard.

# The A and B dictionaries
A = {'a': 1, 'b': 2, 'c': 3}
B = {'b': 3, 'c': 4, 'd': 5}

# The final dictionary. Will contain the final outputs.
newdict = {}

# Make sure every key of A and B get into the final dictionary 'newdict'.
newdict.update(A)
newdict.update(B)

# Iterate through each key of A.
for i in A.keys():

    # If same key exist on B, its values from A and B will add together and
    # get included in the final dictionary 'newdict'.
    try:
        addition = A[i] + B[i]
        newdict[i] = addition

    # If current key does not exist in dictionary B, it will give a KeyError,
    # catch it and continue looping.
    except KeyError:
        continue

EDIT: thanks to jerzyk for his improvement suggestions.