scope of function parameters

[Peter Otten]

Laurent Claessens wrote:

> Le 30/05/2011 11:02, Terry Reedy a écrit :
>> On 5/30/2011 3:38 AM, Laurent wrote:
>>
>>>  Cool. I was thinking that "5" was the name, but
>>>   >>>  5.__add__(6)
>>>  File "<stdin>", line 1
>>>  5.__add__(6)
>>
>>
>> Try 5 .__add__(6)
> 
> What is the rationale behind the fact to add a space between "5" and
> ".__add__" ?
> Why does it work ?

It's a hint for the tokenizer.

$ cat show_tokens.py
import sys

from tokenize import generate_tokens
from cStringIO import StringIO
from token import tok_name

_name_width = max(len(name) for name in tok_name.itervalues())

def show_tokens(s):
    for token in generate_tokens(StringIO(s).readline):
        name = tok_name[token[0]]
        value = token[1]
        print "%-*s %r" % (_name_width, name, value)

if __name__ == "__main__":
    show_tokens(" ".join(sys.argv[1:]))

$ python show_tokens.py 5.__add__
NUMBER           '5.'
NAME             '__add__'
ENDMARKER        ''

$ python show_tokens.py 5 .__add__
NUMBER           '5'
OP               '.'
NAME             '__add__'
ENDMARKER        ''