Creating an If statement within a lumbda function [duplicate]

Question

Is it possible to write an "if statement" into a lambda functions in python? I am trying to write something along these lines but I am getting a syntax error after the if statement:

filt_sin = snf.generic_filter(lambda x: np.std(sin, (size, size) if x<=sin_std), sin, size=size, mode="nearest")

Answer 1

The thing to understand is that whatever single expression is to the right of the : is what your lambda function will return. If you want your lambda to return None under certain conditions, you can use a ternary expression, e.g.:

lambda x: foo(x) if x > y else None

Keywords like if: ... else: ... and for ... in ...: that introduce indented blocks do not work within the scope of a lambda definition, but you can use ternary expressions, generator expressions, etc.