[Zope3-dev] Re: [Zope3-checkins] SVN: Zope3/branches/tlotze/src/zope/interface/interface.py Simplifying some idioms, coding style.

[Benji York]

Thomas Lotze wrote:
> Log message for revision 37985:
>   Simplifying some idioms, coding style.
> 
> Changed:
>   U   Zope3/branches/tlotze/src/zope/interface/interface.py
> 
> -=-
> Modified: Zope3/branches/tlotze/src/zope/interface/interface.py
> ===================================================================
> --- Zope3/branches/tlotze/src/zope/interface/interface.py	2005-08-18 07:12:23 UTC (rev 37984)
> +++ Zope3/branches/tlotze/src/zope/interface/interface.py	2005-08-18 07:57:37 UTC (rev 37985)
> @@ -33,12 +33,8 @@
>  
>  def invariant(call):
>      f_locals = sys._getframe(1).f_locals
> -    tags = f_locals.get(TAGGED_DATA)
> -    if tags is None:
> -        tags = f_locals[TAGGED_DATA] = {}
> -    invariants = tags.get('invariants')
> -    if invariants is None:
> -        invariants = tags['invariants'] = []
> +    tags = f_locals.setdefault(TAGGED_DATA, {})
> +    invariants = tags.setdefault('invariants', [])
>      invariants.append(call)
>      return _decorator_non_return

I didn't review your entire check in (and I realize that this is on a 
branch), but the non-use of setdefault there was probably intentional to 
keep from constructing empty dicts and lists when they may not be used.

>      def getSignatureString(self):
> -        sig = "("
> +        sig = []
>          for v in self.positional:
> -            sig = sig + v
> +            sig.append(v)
>              if v in self.optional.keys():
> -                sig = sig + "=%s" % `self.optional[v]`
> -            sig = sig + ", "
> +                sig[-1] += "=%s" % `self.optional[v]`
>          if self.varargs:
> -            sig = sig + ("*%s, " % self.varargs)
> +            sig.append("*%s" % self.varargs)
>          if self.kwargs:
> -            sig = sig + ("**%s, " % self.kwargs)
> +            sig.append("**%s" % self.kwargs)
>  
> -        # slice off the last comma and space
> -        if self.positional or self.varargs or self.kwargs:
> -            sig = sig[:-2]
> +        return "(%s)" % ", ".join(sig)
>  
> -        sig = sig + ")"
> -        return sig

If you're looking for a simplification here, I'd use "+" rather than "%" 
above, for example:

     sig.append("*" + self.varargs)
-- 
Benji York
Senior Software Engineer
Zope Corporation