On 16/10/17 21:12, Stefan Ram wrote: > r...@zedat.fu-berlin.de (Stefan Ram) writes: >> »x = None« observably has not the same effect as »del x«: > > Paradoxically, /deleting/ a local variable which did not > ever exist, has the effect of creating a ghost of that > local variable which then will hide a global variable: > > Case 1: The global variable »x« can be used in »f« just > fine: > > |>>> x = 9 > |>>> def f(): > |... print( x ) > |... > |>>> f() > |9 > > . Case 2: The »del x« creates a ghost »local variable 'x'« > which now will hide the global variable »x«: > > |>>> x = 9 > |>>> def f(): > |... del x > |... print( x ) > |... > |>>> f() > |UnboundLocalError: local variable 'x' referenced before assignment > > .
That's not what happens. The UnboundLocalError is in the del statement, not the print call: >>> x = None >>> def f(): ... del x ... >>> f() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 2, in f UnboundLocalError: local variable 'x' referenced before assignment >>> -- https://mail.python.org/mailman/listinfo/python-list
