On Sun, 07 Jun 2009 00:21:45 +0800, tsangpo wrote:
> "kj" <[email protected]> 写入消息 news:h0e3p9$85t
[email protected]...
>> In <[email protected]> "tsangpo"
>> <[email protected]> writes:
>>
>>>I want to ensure that the url ends with a '/', now I have to do thisa
>>>like below.
>>>url = url + '' if url[-1] == '/' else '/'
>>
>>>Is there a better way?
>>
>> It's a pity that in python regexes are an "extra", as it were.
>> Otherwise I'd propose:
>>
>> url = re.sub("/?$", "/", url)
>>
>> kynn (lowest-of-the-low python noob)
>
> look nice, but:
>
>>>> re.sub('/?$/', '/', 'aaabbb')
> 'aaabbb'
>
> has no effect. what a pity.
That's because you're doing it wrong. You've added an extra slash: you're
asking the regex engine to match a backslash *after* the end of the
string. Obviously that will never match.
>>> re.sub('/?$/', '/', 'aaabbb') # extra /
'aaabbb'
>>> re.sub('/?$', '/', 'aaabbb') # no extra /
'aaabbb/'
But before you get too excited, see my previous post: the regex solution
is more than ten times slower than test-and-concatenate.
--
Steven
--
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