[Python-checkins] CVS: python/dist/src/Doc/ref ref5.tex,1.51,1.52

[Michael Hudson]

Update of /cvsroot/python/python/dist/src/Doc/ref
In directory usw-pr-cvs1:/tmp/cvs-serv27164

Modified Files:
	ref5.tex 
Log Message:
Fix for

[ #429329 ] actual-parameters *arg, **kws not doc'd



Index: ref5.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/ref/ref5.tex,v
retrieving revision 1.51
retrieving revision 1.52
diff -C2 -d -r1.51 -r1.52
*** ref5.tex	2001/10/01 20:25:26	1.51
--- ref5.tex	2001/12/12 11:56:33	1.52
***************
*** 440,445 ****
               {\token{primary} "(" [\token{argument_list} [","]] ")"}
    \production{argument_list}
!              {\token{positional_arguments} ["," \token{keyword_arguments}]
!               | \token{keyword_arguments}}
    \production{positional_arguments}
               {\token{expression} ("," \token{expression})*}
--- 440,450 ----
               {\token{primary} "(" [\token{argument_list} [","]] ")"}
    \production{argument_list}
!              {\token{positional_arguments} ["," \token{keyword_arguments} 
! 		 ["," "*" \token{expression} ["," "**" \token{expression}]]]
!               | \token{keyword_arguments} ["," "*" \token{expression} 
! 		["," "**" \token{expression}]]
! 	      | "*" \token{expression} ["," "**" \token{expression}]
! 	      | "**" \token{expression}
! 	     }
    \production{positional_arguments}
               {\token{expression} ("," \token{expression})*}
***************
*** 495,498 ****
--- 500,541 ----
  values as corresponding values), or a (new) empty dictionary if there
  were no excess keyword arguments.
+ 
+ If the syntax \samp{*expression} appears in the function call,
+ \samp{expression} must evaluate to a sequence.  Elements from this
+ sequence are treated as if they were additional positional arguments;
+ if there are postional arguments \var{x1},...,\var{xN} , and
+ \samp{expression} evaluates to a sequence \var{y1},...,\var{yM}, this
+ is equivalent to a call with M+N positional arguments
+ \var{x1},...,\var{xN},\var{y1},...,\var{yM}.
+ 
+ A consequence of this is that although the \samp{*expression} syntax
+ appears \emph{after} any keyword arguments, it is processed
+ \emph{before} the keyword arguments (and the \samp{**expression}
+ argument, if any -- see below).  So:
+ 
+ \begin{verbatim}
+ >>> def f(a, b):
+ ...  print a, b
+ ...
+ >>> f(b=1, *(2,))
+ 2 1
+ >>> f(a=1, *(2,))
+ Traceback (most recent call last):
+   File "<stdin>", line 1, in ?
+ TypeError: f() got multiple values for keyword argument 'a'
+ >>> f(1, *(2,))
+ 1 2
+ \end{verbatim}
+ 
+ It is unusual for both keyword arguments and the \samp{*expression}
+ syntax to be used in the same call, so in practice this confusion does
+ not arise.
+ 
+ If the syntax \samp{**expression} appears in the function call,
+ \samp{expression} must evaluate to a (subclass of) dictionary, the
+ contents of which are treated as additional keyword arguments.  In the
+ case of a keyword appearing in both \samp{expression} and as an
+ explicit keyword argument, a \exception{TypeError} exception is
+ raised.
  
  Formal parameters using the syntax \samp{*identifier} or