[New-bugs-announce] [issue12023] non causal behavior

[Rodrigo Ventura]

New submission from Rodrigo Ventura <rodrigo.ventura.isr at gmail.com>:

Consider these two functions:
---
def nok():
    a = None
    def f():
        if a:
            a = 1
    f()

def ok():
    a = None
    def f():
        if a:
            b = 1
    f()
---

Function ok() executes fine, but function nok() trigger an exception:

Traceback (most recent call last):
  File "pb.py", line 20, in <module>
    nok()
  File "pb.py", line 7, in nok
    f()
  File "pb.py", line 5, in f
    if a:
UnboundLocalError: local variable 'a' referenced before assignment

There is no reason for this to happen

Regards,
Rodrigo Ventura

----------
messages: 135380
nosy: Rodrigo.Ventura
priority: normal
severity: normal
status: open
title: non causal behavior
type: behavior
versions: Python 2.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue12023>
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