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Python Python Basics (2015) Logic in Python Containment

Posted by Fernando Mendoza
Fernando Mendoza
345 Points

Ok so if i use the in statement i can create a not in statement and not have to use an else statement for the in state 

color = 'yellow'
colors_available = ['Green', 'Blue', 'Red', 'Black']
if color in colors_available:
    print('Nice color choice buddy')
# Here don't use else statement but then use if not statement
if color not in colors_available:
    print('Choose a better color choice buddy')

# Are those two statements the same as writing
if color in colors_available:
    print('Nice color choice buddy')
else:
    print('Choose a better color choice buddy')

1 Answer

Michael Hulet
Michael Hulet
47,912 Points
Michael Hulet
Michael Hulet
47,912 Points

Yes, they're equivalent. The not operator just takes a boolean and inverts it. If it sees false, it give back true, but if it sees true, it gives back false. So yeah, those methods are equivalent, but the second method is preferred because it creates a clear logical link between the 2 block of code, and it means you don't have to go through all the operations of checking array inclusion for a second time, which can be a computationally expensive thing to do