學習時犯了低階錯誤!!! 把整數和字串進行比較前沒有強轉型別..

num = input('使用者請輸入電話號')
if not num.isdigit():
    print('你輸入的不是數字')

else:
    if len(num) != 11
        print(輸入不正確)

    else:
        tel = num[:3]
        if 130<= int(tel) <=150:

        # if 130<=tel<=150:     # Str和int比較前必須轉為int, 否則報錯!!!
            print('這是移動號')

        elif 150<= int(tel) <=170:
        # elif 150<=tel<=170:
            print('這是聯通號')

        elif 170<= int(tel) <=199:
        # elif 170<=tel<=199:
            print('這是電訊號')

        else:
            print('該手機號不屬於任何運營商')