CODEWITHSUNDEEP
pythontuples
dumb dirty
dumb dirty

Reputation: 15

python "in" operation comparing a string with a tuple of containing only 1 string

I notice a strange behavior of "in" operation when comparing a string with a tuple containing only 1 string.

'monday' in ('not monday')

the result is True
as if we were comparing 2 strings

but if I change the expression by adding another element in the tuple.

'monday' in ('not monday', 'not monday neither')

it returns False as expected.

any idea why?

Upvotes: 0

Views: 289

Answers (2)

normidar
normidar

Reputation: 579

Because the ('not monday') does not mean tuple, it means string as same as 'not monday', if you want to create an only one unit tuple you can write ('not monday',) (add a , to the end).

good luck!

Upvotes: 0

Green Cloak Guy
Green Cloak Guy

Reputation: 24691

>>> 'monday' in ('not monday')
True
>>> 'monday' in ('not monday',)
False

A single-element tuple must have the trailing comma. Otherwise, it gets interpreted as regular order-of-operations parentheses, which are meaningless in this case So, 'monday' in ('not monday') is syntatically identical to 'monday' in 'not monday'.

Upvotes: 6

Related Questions