[Python-Dev] Other library code transformations
Guido van Rossum
Fri, 31 May 2002 12:24:05 -0400
> While we're eliminating uses of the string and types modules, how about
> other code clean-ups and modernization:
In general I'd only do these when you're working on a module anyway.
And again stay out of the larger packages altogether.
> d.has_key(k) --> k in d
> if k in d.keys() --> if k in d
> obj.__dict__ --> vars(obj)
No. vars() exists in the first place to be called without arguments,
to look in the interactive namespace.
> class X(UserList) --> class X(list)
That would be a huge change in semantics.
> class X(UserDict) --> class X(dict) # and remove .data references
> 0L --> 0
> 1L --> 1
Careful -- there are still semantic differences (e.g. 1<<100 == 0,
1L<<100 == 2**100).
> lambda x, y=y: fun(x,y) --> lambda x: fun(x,y)
This changes semantics! If the outer y is later assigned to, the
nested-scopes form tracks that change, the default arg doesn't.
> x = y.__class__ --> x is type(y)
These are not the same! A metaclass can override __class__ but not
type(); also, for a classic class instance type() and __class__ have
> == None --> is None
> if item in astring --> if item in adict
Huh? What does this mean?
> This is from my own list of code updates, the python library already
> in better shape.
I'd rather see effort go towards other things. Have you looked at
--Guido van Rossum (home page: http://www.python.org/~guido/)