Python functional Programming--partial function

1.1   Partial function

Python 's functools module provides a number of useful features, one of which is the partial function. It is important to note that the partial function here is not the same as the partial function in mathematical sense.

When we introduce the function parameters, we can reduce the difficulty of the function call by setting the default value of the parameter.

>>> Import Functools

>>> Int (' 123 ', base = 8)-- converted to 8 binary

83

>>> Int (' 123 ', base = +)-- converted into a binary

291

Functools.partial is helping us to create a biased function.

>>> def int2 (x, base = 2):

... return int (x, Base)

...

>>> int2 (' 11111111111111 ')

16383

>>> Import Functools

>>> int2 =functools.partial (int, base = 2)

>>> int2 (' 11111111111111 ')

16383

The function of functools.partial is to fix certain parameters of a function (that is, to set default values), to return a new function, and to call this new function is simpler.

when you create a partial function, you can actually receive the function object, *args and the **kw it 3 a parameter when passed in:

Int2 = functools.partial (int, base=2)

The keyword parameter base of the int () function is actually fixed , i.e.:

Int2 (' 10010 ')

Equivalent:

KW = {' base ': 2}

Int (' 10010 ', **kw)

Max2 = Functools.partial (max, 10)

will actually automatically add a portion of the *args to the left, namely:

MAX2 (5, 6, 7)

Equivalent:

args = (10, 5, 6, 7)

Max (*args)

The result is ten.

This article is from the "90SirDB" blog, be sure to keep this source http://90sirdb.blog.51cto.com/8713279/1821013

Python functional Programming--partial function