Question

我最近开始学习Python，并且我被分配了创建一个平均字典成绩的函数的任务。

lloyd = {
    "name": "Lloyd",
    "homework": [90.0, 97.0, 75.0, 92.0],
    "quizzes": [88.0, 40.0, 94.0],
    "tests": [75.0, 90.0]
}
alice = {
    "name": "Alice",
    "homework": [100.0, 92.0, 98.0, 100.0],
    "quizzes": [82.0, 83.0, 91.0],
    "tests": [89.0, 97.0]
}
tyler = {
    "name": "Tyler",
    "homework": [0.0, 87.0, 75.0, 22.0],
    "quizzes": [0.0, 75.0, 78.0],
    "tests": [100.0, 100.0]
}


def average(grades):
    total = 0
    grades.sum() = total
    total.float() = total
    total = total / len(grades)
    return total

然而，当执行该功能时，我收到错误，＆＃34;不能分配给功能调用＆＃34;这是什么意思，我该如何解决？

Answer 1

我猜你想要将成绩列表传递给average()函数。

您在grades.sum() = total和total.float() = total

中的语法有些混淆

你（可能）想要这样的东西：

def average(grades):
    total = sum(grades)
    return float(total) / len(grades)

你可以这样称呼这个函数：

avg = average(alice["homework"])

total = sum(grades)表示计算grades中值的总和，并将结果存储在名为total的变量中。函数调用sum(grades)提出一个问题，在Python中（像大多数其他编程语言一样）我们在=符号的右侧侧写下问题，并且将答案放在=符号的左侧侧。但是你的代码反过来了。

Answer 2

您正在为内置函数的返回值赋值，这是不可能的。试试这个

lloyd = {
"name": "Lloyd",
"homework": [90.0, 97.0, 75.0, 92.0],
"quizzes": [88.0, 40.0, 94.0],
"tests": [75.0, 90.0]
}
alice = {
"name": "Alice",
"homework": [100.0, 92.0, 98.0, 100.0],
"quizzes": [82.0, 83.0, 91.0],
"tests": [89.0, 97.0]
}
tyler = {
"name": "Tyler",
"homework": [0.0, 87.0, 75.0, 22.0],
"quizzes": [0.0, 75.0, 78.0],
"tests": [100.0, 100.0]
}


def average(grades):
    total = 0
    total = grades.sum()
    total = total.float()
    total = total / len(grades)
    return total

Answer 3

而不是：

grades.sum() = total

你宁愿这样做：

total = grades.sum()

如果你想深入挖掘，这里有 explanation of the whys and hows 。

什么不能分配给函数调用mean（python）

3 个答案: