False positive on R504

[nijel]

• Date you used flake8-return: 2019-05-16
• flake8-return version used, if any: 1.0.0
• Python version, if any: 3.7.1
• Operating System: Debian

Description

The R504 doesn't detect that the variable is conditionally modified prior to return.

What I Did

$ flake8 test.py 
test.py:5:12: R504 you shouldn`t assign value to variable if it will be use only as return value
$ cat test.py
def foo(bar):
    value = []
    if bar:
        value = value[:1]
    return value

[afonasev]

Hello. Linter offers to immediately make a return, instead of changing the value of a variable that will no longer be used or changed. i.e.

def foo(bar):
    value = []
    if bar:
        return value[:1]
    return value

[nijel]

Okay, it might be reasonable in some situations with if, but let's take another example with for:

def clean_fullname(val):
    """Remove special chars from user full name."""
    val = val.strip()
    for i in range(0x20):
        val = val.replace(chr(i), '')
    return val

[afonasev]

it looks like a bug, I'll try to fix it soon, thx