Python代码，名称未定义错误

Question

我正在尝试在 letter_grade 函数中引用 student_avg 函数，但似乎 student_avg 这个参数没有被识别。

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(numbers):
    total = sum(numbers)
    total = total/len(numbers)
    return total

def student_avg(student):
    """Returns weighted average"""
    homework = average(student['homework']) * 10/100
    quizzes = average(student['quizzes']) * 30/100
    tests = average(student['tests']) * 60/100
    return homework + quizzes + tests

def lett_grade(studentname):
 """   Gets the students letter grade A-F"""
if student_avg(studentname)  >= 90:
    print('A')
elif 90 > student_avg(studentname) >= 80:
    print('B')
elif 80 > student_avg(studentname) >= 70:
    print('C')
elif 70 > student_avg(studentname) >= 60:
    print('D')
else:
    print('F')

我遇到了这个错误：

Traceback (most recent call last):
  File "/Users/Anthony/Documents/class.py", line 34, in <module>
  if student_avg(studentname)  >= 90:
NameError: name 'studentname' is not defined

另外，为什么在最后一个函数中我不应该缩进 if 和 elif 语句？我在前两个函数中缩进了其他所有内容——这只是语法问题吗？

Answer 1

你的问题在于缩进。

在你的函数 lett_grade(student name) 中，里面只有 """ 获取学生的字母成绩 A-F""" 这句话。

所以，if 语句就不在这个函数里面，这样 studentname 就没有定义。

这是你修改过的代码：

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(numbers):
    total = sum(numbers)
    total = total/len(numbers)
    return total

def student_avg(student):
    """Returns weighted average"""
    homework = average(student['homework']) * 10/100
    quizzes = average(student['quizzes']) * 30/100
    tests = average(student['tests']) * 60/100
    return homework + quizzes + tests

def lett_grade(studentname):
 """   Gets the students letter grade A-F"""
    if student_avg(studentname)  >= 90:
        print('A')
    elif 90 > student_avg(studentname) >= 80:
        print('B')
    elif 80 > student_avg(studentname) >= 70:
        print('C')
    elif 70 > student_avg(studentname) >= 60:
        print('D')
    else:
        print('F')