python中partial库的使用方法解析_python

class partial:
    """New function with partial application of the given arguments
    and keywords.
    """

from functools import partial
 
# 定义一个加法函数
def add(a, b, c):
    return a + b + c
# 定义分部函数，其中第一个参数已经固定
ret = partial(add, 6)
# 初始化前两个参数并打印
print(ret(2, 4))

from functools import partial
 
# 定义一个求幂函数
def sq(a, b):
    return b ** a
# 求平方   分部函数   第一个参数已经确定
pingfang = partial(sq, 2)
# 求立方   分部函数   第一个参数已经确定
lifang = partial(sq, 3)
# 求5的平方
print(pingfang(5))
# 求5的立方
print(lifang(5))

from functools import partial
import requests
 
def get_baidu(method, url):
    response = requests.request(method=method, url=url)
    return response.content
 
res = get_baidu("get", "https://www.baidu.com")
print(res)
# 将函数和参数封装到一个指定变量名中,下次执行直接调用加()
getBaidu = partial(get_baidu, 'get', "https://www.baidu.com")
print(type(getBaidu))  # <class 'functools.partial'>
ret = getBaidu()
print(ret)

from functools import partial
 
# 定义一个加减乘除的类
class Calculate(object):
    md = ["add", "minus", "multiplication", "division"]
 
    def __init__(self, method, num1=0, num2=0):
        self.num1 = num1
        self.num2 = num2
        if method in self.md:
            func = getattr(Calculate, method)
            print(func)
            self.result = func(self)
 
    def add(self):
        return self.num1 + self.num2
 
    def minus(self):
        return self.num1 - self.num2
 
    def multiplication(self):
        return self.num1 * self.num2
 
    def division(self):
        return self.num1 / self.num2
 
add = partial(Calculate, "add")
minus = partial(Calculate, "minus")
multiplication = partial(Calculate, "multiplication")
division = partial(Calculate, "division")
 
print(add)
print(minus)
print(multiplication)
print(division)
 
print("*" * 100)
 
print(add(3, 5))
print(add(3, 5).result)
print(minus(3, 5).result)
print(multiplication(3, 5).result)
print(division(3, 5).result)