gervaz <ger...@gmail.com> writes: > Hi all, can you explain me why this simple function works well (i.e. I > can call the print function using txt) in py > > >>> def test(value): > ... if value%5: txt = "hello" > ... else: txt = "test" > ... print(txt) > > while in other languages like C the txt identifier would be undefined?
Python doesn't have variables the way C or many other languages have them. Instead, Python has objects, and references to those objects so you can get at them. The Python documentation, much to my frustration, calls these references “variables” even though that gives exactly the wrong implication of how they'd behave. With the assignment statements (the statements using ‘txt = …’), the name ‘txt’ is bound as a reference to a value. It's not a C-like variable; it doesn't have a type, it doesn't need to be declared, etc. It's just a name, that you can bind to exactly one value any time you like. > Is there a way to force the scoping? No, by binding a name to a value you are creating that binding within the scope where the binding happens (the assignment statement, in your example). -- \ “Instead of a trap door, what about a trap window? The guy | `\ looks out it, and if he leans too far, he falls out. Wait. I | _o__) guess that's like a regular window.” —Jack Handey | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
