正确添加

Question

我必须定义一个接受字符串列表的函数。推，弹，看。

def digit_stack(commands):
    stack = []
    sums = 0
    for i in commands:
        if "PUSH" in i:
            for n in i:
                if n.isdigit():
                    stack.append(int(n))
        return stack

然而

digit_stack("PUSH 3", "PUSH 4") == [3]

为什么只是追加第一推？

Answer 1

第一次迭代后你return：

for i in commands:
    if "PUSH" in i:
        for n in i:
            if n.isdigit():
                stack.append(int(n))
return stack # move outside the loop