[Python-ideas] strtr? (was startsin ?

[INADA Naoki]

I think `strtr`_ in php is also very useful when escaping something.

_ strtr: http://jp.php.net/manual/en/function.strtr.php

For example:

.. code-block:: php

    php> = strtr("foo\\\"bar\\'baz\\\\", array("\\\\"=>"\\",
'\\"'=>'"', "\\'"=>"'"));
    "foo\"bar'baz\\"

.. code-block:: python

    In [1]: "foo\\\"bar\\'baz\\\\".replace('\\"', '"').replace("\\'",
"'").replace('\\\\', '\\')
    Out[1]: 'foo"bar\'baz\\'

In Python, lookup of 'replace' method occurs many times and temporary
strings is created many times too.
It makes Python slower than php.

And replacing order may cause very common mistake.

.. code-block:: python

    In [4]: "foo\\\"bar\\'baz\\\\'".replace('\\\\',
'\\').replace('\\"', '"').replace("\\'", "'")
    Out[4]: 'foo"bar\'baz\''


When I wrote HandlerSocket_ client in pure Python. I use dirty hack for speed.

  http://bazaar.launchpad.net/~songofacandy/+junk/pyhandlersocket/view/head:/handlersocket/client.py

I believe Pythonic means simple and efficient. My code is not Pythonic at all.

.. _HandlerSocket: https://github.com/ahiguti/HandlerSocket-Plugin-for-MySQL


On Sat, Oct 1, 2011 at 12:30 AM, Tarek Ziadé <ziade.tarek at gmail.com> wrote:
> Hey,
>
> not sure how people do this, or if I missed something obvious in the
> stdlib, but I often have this pattern:
>
> starts = ('a', 'b', 'c')
> somestring = 'acapulco'
>
> for start in starts:
>    if somestring.startswith(start):
>        print "yeah"
>
>
> So what about a startsin() method, that would iterate over a sequence:
>
> if somestring.startsin('a', 'b', 'c'):
>    print "yeah"
>
> Implementing it in C should be faster as well
>
> same deal with .endswith I guess
>
> Cheers
> Tarek
>
> --
> Tarek Ziadé | http://ziade.org
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>



-- 
INADA Naoki  <songofacandy at gmail.com>