Either all return statements in a function should return an expression, or none of them should.
419
420
421@decorator
422def check_matplotlib_available(func, *args, **kwargs):423 """Emit a warning if matplotlib is not available."""
424
425 def _warn():
Description
According to PEP8, if any return statement returns an expression, any return statements where no value is returned should explicitly state this as return None, and an explicit return statement should be present at the end of the function (if reachable).
Good:
def foo(x):
if x >= 0:
return math.sqrt(x)
else:
return None
def bar(x):
if x < 0:
return None
return math.sqrt(x)
Bad:
def foo(x):
if x >= 0:
return math.sqrt(x)
def bar(x):
if x < 0:
return
return math.sqrt(x)