如何使用字典为每个学生存储多个条目

Question

这是问题陈述：

有“n”个学生的记录，每个记录都有学生姓名、数学、物理和化学获得的百分比。用户输入一个整数“n”，后跟“n”个学生的姓名和分数。我需要将记录保存在字典数据类型中。然后，用户输入学生姓名，您需要打印该学生获得的平均百分比分数，更正到小数点后两位。到目前为止我已经尝试过：

num_students = int(raw_input("Please enter number of students:"))
print "you entered %s students" %num_students
student_info = {}
student_data = ['studentname', 'mathmarks', 'physicsmarks', 'chemistrymarks']
for i in range(0,num_students):
    for entry in student_data:
        student_info[entry] = raw_input(entry )
print student_info
print"please enter student name"
name = raw_input("student name")
if student_info['studentname'] == name:
    print "Average student marks:", (int(student_info['mathmarks']) + int(student_info['physicsmarks']) + int(student_info['chemistrymarks']))/3
else:
    print"please enter valid name"

此代码在 num_students = 1 时有效，但是如果 num_students >1 则代码失败。

我无法保存字典中每个学生的条目。

我对 python 很陌生，如果有人能帮助我，我会很高兴。

Answer 1

实际上，您需要创建一个嵌套字典，其中名称作为值，另一个字典作为键，嵌套字典可能看起来像这样：

{
    'anmol': {'chemistrymarks': 3, 'physicsmarks': 2, 'mathmarks': 1},
    'uppal': {'chemistrymarks': 6, 'physicsmarks': 5, 'mathmarks': 4}
}

因此，您需要添加以下行来创建嵌套字典。

num_students = int(raw_input("Please enter number of students:"))
print "you entered %s students" %num_students
student_info = {}
student_data = ['Math marks : ', 'Physics marks : ', 'Chemistry marks : ']
for i in range(0,num_students):
    student_name = raw_input("Name :")
    student_info[student_name] = {}
    for entry in student_data:
        student_info[student_name][entry] = int(raw_input(entry)) #storing the marks entered as integers to perform arithmetic operations later on.
#print student_info
print"Please enter student name ?"
name = raw_input("Student name : ")
if name in student_info.keys():
    print "Average student marks : ", str(sum(student_info[name].values())/3.0)
else:
    print"please enter valid name"