python - Merging global and local scopes -


if works

x=5 def main():     globe in locals():         globals().update(locals()[globe])     print x main()

then why doesn't this?

x=5 def main():     globe in locals():         globals().update(locals()[globe])     x+=1     print x main()

the error in latter statement claims x referenced before assignment, works in first example...

you cannot assign global variable in python without explicitly doing so. writing x+=1 assigning value x , implicitly declaring x local variable. not defined , therefore error.

the loop has no actual effect, locals dictionary empty.

if want use global variables in python (which shouldn't, that's matter), should use global keyword.


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