Python Argument Binders

Using functools.partial:

>>> from functools import partial
>>> def f(a, b):
...     return a+b
... 
>>> p = partial(f, 1, 2)
>>> p()
3
>>> p2 = partial(f, 1)
>>> p2(7)
8

functools.partial returns a callable wrapping a function with some or all of the arguments frozen.

import sys
import functools

print_hello = functools.partial(sys.stdout.write, "Hello world\n")

print_hello()

Hello world

The above usage is equivalent to the following lambda.

print_hello = lambda *a, **kw: sys.stdout.write("Hello world\n", *a, **kw)

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