Passing a parameter to filter

[Fredrik Lundh]

Thomas Philips wrote:

> Now, I try to filter a range using
> >>> filter(f(k=3),range(20))

f(k=3) calls the function, so you're passing the return value to filter,
not the function itself.  that's obviously not what you want.

some alternatives:

    filter(lambda x: f(x, 3), range(20))

    [x for x in range(20) if f(x, 3)]

the lambda form creates an "anonymous function" that takes one
argument, and calls your f() function with the right arguments.

the second form is a "list comprehesion", which is a compact way
to write for-in loops.

</F>

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