高效的循环方式

Question

I have the following code and it works but as I want to master my skills in python I would like to get your opinion how to improve the code and make it efficient. x

value - certain value user selects

a=[10,30,50,20]


def math():
    if value =='Math':return a[0]
    if value =='Biology':return a[1]
    if value =='Chemistry':return a[2]
    if value =='Literature':return a[3]

Is there any way to loop automatically a[0:] with values given? I was thinking of dictionary but here I am given conditional statements. Any help would be appreciated.

Answer 1

Yes, a dictionnary would be an appropriate structure.

grades = {"Math": 10,
          "Biology": 30,
          "Chemistry": 50,
          "Literature": 20}

topic = input()
try:
    print(grades[topic])
except KeyError:
    print(f'There is no available grade for the topic "{topic}".')

Answer 2

This can be alternate, like switch-case (since python dose not have switch-case statements) in other languages. You can try the below code:

def switch_case(arg):
    switcher = {
        'Math' : 10,
        'Biology' : 30,
        'Chemistry' : 50,
        'Literature' : 20
    }
    return switcher.get(arg, 'Invalid subject!')

subject = input('Enter the subject : ')
print(switch_case(subject))