Why does dict(k=4, z=2).update(dict(l=1)) return None in Python?

Question

Why does dict(k=4, z=2).update(dict(l=1)) return None? It seems as if it should return dict(k=4, z=2, l=1)? I\'m using Python 2.7 shou

Answer 1

dict.update() method does update in place. It does not return the modified dict, but None.

The doc says it in first line:

Update the dictionary with the key/value pairs from other, overwriting existing keys. Return None.