Feature Requests item #1122279, was opened at 2005-02-14 05:40 Message generated for change (Comment added) made by tjreedy You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1122279&group_id=5470
Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Zac Evans (karadoc) Assigned to: Nobody/Anonymous (nobody) Summary: Option to force variables to be declared Initial Comment: My most common python programming error is to spell a variable different ways in different parts of a program. Often this generates no warnings, and is a difficult problem to track down. The Zen of Python says that 'Explicit is better than Implicit'. I would like it if I could set an option so that I had to explicitly declare variables before I can use them. eg. x = 5 would generate a warning, but x = int() x = 5 would not. I do believe that explicit is better than implicit with respect to programming; and I know that this feature would save me a _lot_ of debugging on my larger python projects. ---------------------------------------------------------------------- Comment By: Terry J. Reedy (tjreedy) Date: 2005-02-16 20:09 Message: Logged In: YES user_id=593130 x = int() does not 'declare' x. It binds it to the result of calling int without any arguments, which is 0. >>> int() 0 So it is the same as x = 0. Various ideas about declarations and finding typos have been discussed on comp.lang.python and elsewhere. You might review some of the c.l.p threads, possibly via Google. ---------------------------------------------------------------------- Comment By: Brett Cannon (bcannon) Date: 2005-02-15 14:29 Message: Logged In: YES user_id=357491 This will never get in as proposed for technical reasons. What is the difference between ``x=5`` and ``x=int()``? To the compiler they are just assignments to a variable, one just happens to involve a function call. The only way to get the feature you want is to somehow have a more specific way of declaring variables, like a 'var' keyword or something and that will probably never go. As Jim suggested, PyChecker is great for this kind of thing. There are things in the works to help lead to PyChecker being added to the standard library so your problem should get a partial solution included in Python some time in the future. ---------------------------------------------------------------------- Comment By: Jim Jewett (jimjjewett) Date: 2005-02-15 12:57 Message: Logged In: YES user_id=764593 For various reasons, this won't soon get into the core. Meanwhile, there are some tools like pychecker which may help. I've also found that declaring __slots__ makes the errors surface a little bit faster, when I'm dealing with attributes. (The most common reason for me to need the variable name in widely separated places.) ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1122279&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
