juliosergio at gmail
Jun 12, 2012, 10:53 AM
Views: 440
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using identifiers before they are defined
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I'm puzzled with the following example, which is intended to be a part of a
module, say "tst.py":
a = something(5)
def something(i):
return i
When I try:
->>> import tst
The interpreter cries out:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "tst.py", line 11, in <module>
a = something(5)
NameError: name 'something' is not defined
I know that changing the order of the definitions will work, however there are
situations in which referring to an identifier before it is defined is
necessary, e.g., in crossed recursion.
So I modified my module:
global something
a = something(5)
def something(i):
return i
And this was the answer I got from the interpreter:
->>> import tst
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "tst.py", line 12, in <module>
a = something(5)
NameError: global name 'something' is not defined
Do you have any comments?
Thanks,
--Sergio.
--
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using identifiers before they are defined
