python判斷成績等級思路與實現

方法一：使用正則表達式

import re
while True:
    score = (input("請輸入成績:"))
    if score.isdigit():
        score = int(score)
    elif (re.match('^\d+\.\d+$',score)):
        score = float(score)
    else:
        if score.lower()=='q':
            break
        else:
            print("請輸入0到100數字")
            continue

    if 0<=score<=100:
        if 90<=score<=100:
            print("A")
        elif 80<=score<90:
            print("B")
        elif 60<=score<80:
            print("C")
        elif 0<=score<60:
            print("D")
    else:
        print("輸入有誤")
        continue


二、使用isdigit（）判斷是否為整數實現

while True:
    score = (input("請輸入成績:"))
    if len(str(score))<=5:

        if score.lower() == 'q':
            break
        elif score=='':
            continue
        _score=score.replace('.','',1)
        if _score.isdigit():
            if _score == score:
                score = int(score)
            else:
                score = float(score)
            if 90<=score<=100:
                print("A")
            elif 80<=score<90:
                print("B")
            elif 60<=score<80:
                print("C")
            elif 0<=score<60:
                print("D")
        else:
            print("輸入有誤")
            continue
    else:
        print("請輸入0到100數字，小數點最多2位")
        continue

方式三：使用異常處理

def Score():
    while True:
        score = (input("請輸入成績:"))
        if score.lower() == 'q':
             break
        try:
            score = float(score)
            if 90<=score<=100:
                print("A")
            elif 80<=score<90:
                print("B")
            elif 60<=score<80:
                print("C")
            elif 0<=score<60:
                print("D")
            else:
                print('請輸入0到100之間')
        except ValueError as e:
             print('輸入有誤，錯誤信息為:%s'%e)