[Tutor] Global/Local confusions

[John Abbe]

In my continuing effort to understand global / local interactions --

========================================
#!/usr/local/bin/python
"""
Running this file generates this error:

Traceback (most recent call last):
   File "./gltest", line 10, in ?
     f(9)
   File "./gltest", line 6, in f
     if x in b:
UnboundLocalError: local variable 'b' referenced before assignment
"""

b = [9, 10]

def f(x):
    if x in b:
       print "spam"
    b = [11, 12]       # if this line is commented out, there's no error!

f(9)
========================================

Any explanations? Life,
John
-- 
  All you  /\/\ John Abbe           "If you don't like the news,
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