boolean - Printable Version

boolean - Printable Version

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boolean - bloomyhood - Nov-21-2019

Can anybody explain why:

'b' in 'abc' == 'a' in 'abc'

is

False

Thank you

RE: boolean - ThomasL - Nov-21-2019

Must have something to do with the "in" keyword

print('b' in 'abc' == 'a' in 'abc')
print(('b' in 'abc') == 'a' in 'abc')
print('b' in 'abc' == ('a' in 'abc'))
print(('b' in 'abc') == ('a' in 'abc'))

Output:False
False
False
True

RE: boolean - snippsat - Nov-21-2019

It has to do with chaining comparison operators.
So what's really happens is:

>>> 'b' in 'abc' == 'a' in 'abc'
False

>>> # The chaining is 
>>> ('b' in 'abc') and ('abc' == 'a') and ('a' in 'abc')
False

>>> # After ('abc' == 'a') the result is False and last ('a' in 'abc') is not evaluated   
>>> ('abc' == 'a') 
False

Should avoid to use == like this as it can give unexpected result.
If most use it so dos () break the chaining.

>>> ('b' in 'abc') == ('a' in 'abc')
True