How to improve a double if statement

Question

I would like to optimize this statement:

if 'key' in dictionary and dictionary['key']!=value:

Is there a way to check if a key exists in a dictionary and check the value at the same time?

Answer 1

Use the .get() dict method, which returns None if the key is not in the dictionary instead of throwing a KeyError exception:

d = {'a':0,'b':1}
if d.get('a')==0:
   # you will enter this if-statement
if d.get('c')==0:
   # you will not enter this if-statement and will not throw a KeyError

Answer 2

Python dict has a get() method. For example, if d is a dict, d.get(x, y) returns d[x] if it exists, otherwise it returns y. This means that your if statement can be replaced with if dictionary.get(key, value) != value.