Python编程functools模块创建修改的高阶函数解析

from functools import partial
# 原函数声明
def show(name, level):
    print("name:", name, "level:", level)
# 定义偏函数，封装 show() 函数，并为 name 参数设置了默认参数
show_level = partial(show, name='橡皮擦')
# 由于 name 参数已经有默认值，调用偏函数时，name 可以不指定
show_level(level="9级")

# 代码写成下述内容
show_level("9级")
# 异常如下
TypeError: show() got multiple values for argument 'name'

# 代码写成下述内容
show_level("9级")
# 异常如下
TypeError: show() got multiple values for argument 'name'

@functools.lru_cache(maxsize=None, typed=False)

from functools import lru_cache
import timeit
@lru_cache()
def factorial(n):
    return 1 if n <= 1 else n * factorial(n - 1)
a = timeit.timeit(stmt="factorial(20)", setup='from __main__ import factorial', number=100000)
print(a)

from functools import reduce
def add(x, y):
    return x + y
a = reduce(add, [1, 2, 3, 4])
print(a)

from functools import reduce
a = reduce(lambda x, y: x + y, [1, 2, 3, 4], 2)
print(a)

from functools import reduce
data = [1, 2, 3, 4]
sum = lambda data: reduce(lambda x, y: x + y, data, 0)
count = lambda data: reduce(lambda x, y: x + 1, data, 0)
min = lambda data: reduce(lambda x, y: x if x < y else y, data)
a = sum(data)
b = count(data)
c = min(data)
print(a, b, c)

from functools import reduce, partial
data = [1, 2, 3, 4]
sum = partial(reduce, lambda x, y: x + y)
a = sum(data)
print(a)