[Python-Dev] doc behavior in class definitions (original) (raw)

Jack Diederich jack at performancedrivers.com
Fri Oct 7 22:52:37 CEST 2005

On Fri, Oct 07, 2005 at 12:15:04PM -0700, Martin Maly wrote:

Hello Python-Dev,

My name is Martin Maly and I am a developer at Microsoft, working on the IronPython project with Jim Hugunin. I am spending lot of time making IronPython compatible with Python to the extent possible. I came across a case which I am not sure if by design or a bug in Python (Python 2.4.1 (#65, Mar 30 2005, 09:13:57)). Consider following Python module: # module begin "module doc" class c: print doc doc = "class doc" (1) print doc [snip] Based on the binding rules described in the Python documentation, I would expect the code to throw because binding created on the line (1) is local to the class block and all the other doc uses should reference that binding. Apparently, it is not the case. Is this bug in Python or are doc strings in classes subject to some additional rules?

Classes behave just like you would expect them to, for proper variations of what to expect wink.

The class body is evaluated first with the same local/global name lookups as would happen inside another scope (e.g. a function). The results of that evaluation are then passed to the class constructor as a dict. The new method of metaclasses and the less used 'new' module highlight the final step that turns a bucket of stuff in a namespace into a class.

import new A = new.classobj('w00t', (object,), {'doc':"no help at all", 'myself':lambda x:x}) a = A() a.myself() <__main__.w00t object at 0xb7bc32cc> a <__main__.w00t object at 0xb7bc32cc> help(a) Help on w00t in module main object:

class w00t(builtin.object) | no help at all |
| Methods defined here: |
| lambdax |

Hope that helps,

-jackdied

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