You have three ways to do what you want :
First wayt is to use lambda. Then, you want to write :
>>> map(lambda x: re.sub("[a-z]", "", x), test)Second is to use regular named function :
>>> def remove_letters( s ):
... re.sub("[a-z]", "", s)
>>> map(remove_letters, test)A third way would be to use the "pseudo-currying" described there : http://www.python.org/moin/PythonDecoratorLibrary
In fact, you need a small generalisation :
>>> class curried(object): ... def __init__(self, func, *a, **kw): ... self.func = func ... self.args = a ... self.kwords = kw ... def __call__(self, *a, **kw): ... args = self.args + a ... kwords = dict(self.kwords) ... kwords.update(kw) ... if len(args)+len(kwords) < self.func.func_code.co_argcount: ... return curried(self.func, *args, **kwords) ... else: ... return self.func(*args, **kwords)
The difference is you can handle the kwords with that version ! Then you want to write this :
>>> curried_sub = curried(re.sub)
>>> map(curried_sub("[a-z]", "", count=0), test)My opinion is : the simplest and best solution more "pythonic" is the second one ! The third one is interesting but work only for functions written in Python ! (Hopefully the re.sub function is written in Python). The biggest problem with the first one is that lambda are planned to disappear in future Python versions ...
Pierre
Stu a écrit :
I have recently switched over to Python from Perl. I want to do something like this in Python:
@test = ("a1", "a2", "a3"); map {s/[a-z]//g} @test; print @test;
However, I take it there is no equivalent to $_ in Python. But in that case how does map pass the elements of a sequence to a function? I tried the following, but it doesn't work because the interpreter complains about a missing third argument to re.sub.
import re test = ["a1", "a2", "a3"] map(re.sub("[a-z]", ""), test) print test Thanks in advance.
Regards, Stuart <stuart AT zapata DOT org>
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