Is implicit underscore assignment documented anywhere? I've seen reference to this, and it seems to be simply that, when Python interactively prints a value in response to a user entering an expression, that value is assigned to the variable _.
As far as I can tell, the following transcript shows its workings: ActivePython 2.4.3 Build 12 (ActiveState Software Inc.) based on Python 2.4.3 (#69, Apr 11 2006, 15:32:42) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> _ Traceback (most recent call last): File "<stdin>", line 1, in ? NameError: name '_' is not defined >>> a = 0 >>> _ Traceback (most recent call last): File "<stdin>", line 1, in ? NameError: name '_' is not defined >>> a 0 >>> _ 0 >>> >>> a = 5 >>> _ 0 >>> a 5 >>> _ 5 >>> a = 5 >>> _ 0 >>> a 5 >>> _ 5 >>> #value unchanged, because a's value was not printed (the interpreter does not print None). ... >>> a = 10 >>> print a 10 >>> _ 5 >>> # value unchanged, because print is a statement, not an expression. ... >>> Is this documented anywhere? _______________________________________________ Tutor maillist - [email protected] http://mail.python.org/mailman/listinfo/tutor
