Because it is dynamically typed, Python does not enforce a return type on a function. This means that different paths through a function can return
different types of values, which can be very confusing to the user and significantly harder to maintain.
In particular, it is consequently also possible to mix empty return statements (implicitly returning None) with some
returning an expression. This rule verifies that all the return statements from a function are consistent.
Noncompliant code example
def foo(a): # Noncompliant, function will return "true" or None
if a == 1:
return True
return
Compliant solution
def foo(a):
if a == 1:
return True
return False
or
def foo(a):
if a == 1:
return True
return None
