Python 改变变量参数的函数

Question

我如何重写我的函数，以便在它运行时更改作为参数输入的变量？我读过你必须在每个变量名之前写 global 但在 a、b、c 参数之前写 global 不起作用，我想不出另一个让它工作的方法。

import sys

sys.stdin = open("/Users/isym444/Desktop/PythonCP/CP1/Codewars/Practice/input.txt", "r")
sys.stdout = open("/Users/isym444/Desktop/PythonCP/CP1/Codewars/Practice/output.txt", "w")

""" sys.stdin = open("mixmilk.in", "r")
sys.stdout = open("mixmilk.out", "w") """

c1, m1 = map(int, input().split())
c2, m2 = map(int, input().split())
c3, m3 = map(int, input().split())


def fun1(a, b, c):
    amt = min(a, b - c)
    a -= amt
    c += amt


# pours 1 to 99
for i in range(1, 34):
    fun1(m1, c2, m2)
    fun1(m2, c3, m3)
    fun1(m3, c1, m1)
# pour 100
fun1(m1, c2, m2)

result = [m1, m2, m3]
for i in result:
    print(i)

请注意，这是 USACO 问题的解决方案：2018 年 12 月竞赛，铜牌问题 1. 混合牛奶 -> http://www.usaco.org/index.php?page=viewproblem2&cpid=855

Answer 1

我想这就是您要找的：

[...]
def fun1(a, b, c):
    amt = min(a, b - c)
    a -= amt
    c += amt
    return (a, b, c)

# pours 1 to 99
for i in range(1, 34):
    m1, c2, m2 = fun1(m1, c2, m2)
    m2, c3, m3 = fun1(m2, c3, m3)
    m3, c1, m1 = fun1(m3, c1, m1)
# pour 100
m1, c2, m2 = fun1(m1, c2, m2)
[...]

Python 改变变量参数的函数

Python function that changes variable parameters

python

function

global-variables