Roman,
According to the Python call syntax definition
(http://docs.python.org/ref/calls.html) commas should be allowed, so it
seems like a minor bug. Here are the lines in question:
-----http://docs.python.org/ref/calls.html-----------
call ::= primary "(" [argument_list [","]] ")"
argument_list::=positional_arguments ["," keyword_arguments] ["," "*"
expression] ["," "**" expression]
| keyword_arguments ["," "*" expression] ["," "**" expression]
| "*" expression ["," "**" expression]
| "**" expression
----------------------------------------------------------
If you notice in the 'call' definition, no matter what the
'argument_list' is, it can be followed by an optional ',' right before
the closing ')'. Your code is a counterexample to this. Here is a more
exhaustive example:
--------------------------------------------------------
>>> def f(a,b):
... pass
...
>>> f(1,2)
>>> f(1,2,)
>>> f(1,*[2])
>>> f(1,*[2],)
File "<stdin>", line 1
f(1,*[2],)
^
SyntaxError: invalid syntax
>>> f(1,**{'b':2})
>>> f(1,**{'b':2},)
File "<stdin>", line 1
f(1,**{'b':2},)
^
SyntaxError: invalid syntax
>>> f(*[1,2])
>>> f(*[1,2],)
File "<stdin>", line 1
f(*[1,2],)
^
SyntaxError: invalid syntax
>>> f(**{'a':1,'b':2})
>>> f(**{'a':1,'b':2},)
File "<stdin>", line 1
f(**{'a':1,'b':2},)
^
SyntaxError: invalid syntax
>>>
>>> f(1,b=2)
>>> f(1,b=2,)
>>> f(a=1,b=2,)
>>>
-----------------------------------------------------
Anybody else knows more about this?
/invoking the spirit of GvR... ;-)
Nick Vatamaniuc
Roman Susi wrote:
> Hi!
>
> it is interesting that I found this syntax error:
>
> >>> a = {}
> >>> str('sdfd', **a,)
> File "<stdin>", line 1
> str('sdfd', **a,)
> ^
> SyntaxError: invalid syntax
>
>
> I just wonder is it intentional or by-product (bug or feature)?
> (The behaviour makes sense, of course... I tend to leave commas when I
> expect a list to be added to (i.e. almost always ;-)))
>
>
> Regards,
> Roman
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