How can I do this (from Perl) in Python? (closures)
excord80 at gmail.com
excord80 at gmail.com
Thu Dec 4 00:18:53 EST 2008
I just came across http://www.perl.com/pub/a/2002/05/29/closure.html
and wanted to try the "canonical example of closures" in Python. I
came up with the following, but it fails:
#######################
#!/usr/bin/env python
def make_counter(start_num):
start = start_num
def counter():
start += 1
return counter
from_ten = make_counter(10)
from_three = make_counter(3)
print from_ten() # 10
print from_ten() # 11
print from_three() # 3
print from_ten() # 12
print from_three() # 4
####################
The error message is: "UnboundLocalError: local variable 'start'
referenced before assignment". The same thing happens if I omit start
and just use start_num directly.
How can I do it in Python?
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