Find the lowest value that is not null using python

问题

I have used min(A,B,C,D) in python. This works perfectly in finding the lowest value, however, if I have a null value (0 value) in any of the varaibles A,B,C or D, it would return the null value (or 0). Any ideas how to return the non-null or non-zero value in my case? thanks

回答1:

I would go with a filter which will handle None, 0, False, etc...

>>> min(filter(None, [1, 2, 0, None, 5, False]))
1

From the docs:

Note that filter(function, iterable) is equivalent to [item for item in iterable if function(item)] if function is not None and [item for item in iterable if item] if function is None

回答2:

This pushes any 0 to the other end (max end)

min(A, B, C, D, key=lambda x:(x==0, x))

Or you can use a generator expression

min(x for x in (A, B, C, D) if x)

Using filter

min(filter(None, (A, B, C, D))

Finally, using itertools.compress

from itertools import compress
min(compress((A, B, C, D), (A, B, C, D)))

回答3:

min(v for v in (A,B,C,D) if not v in (None,0))

来源：https://stackoverflow.com/questions/21084714/find-the-lowest-value-that-is-not-null-using-python