Python simple shopping cart

product_list =[ 
    ('huawei',3000), 
    ('hongmiNote3',3000), 
    ('sanxing',2600), 
    ('ThinkPad870',15000), 
    ('Iphone8',5600), 
    ('HuaweiP20',3300) 
]#Commodity list 
shopping_list = []#Shopping list 
while True: 
    salary = input('Input you salary:') 
    #Input salary if salary.isdigit(): #Determine whether the input salary is a number 
        salary = int(salary) 
        while True: 
            for index,item in enumerate(product_list): #Print the product list 
                print(index,item) 
            user_choice = input('What do you want to buy? (Please enter quit to exit):') #Enter the product serial number 
            if user_choice.isdigit( ): 
                user_choice = int(user_choice)
                if user_choice < len(product_list) and user_choice > 0: #Determine whether the product serial number is in the product list 
                    p_item = product_list[user_choice] 
                    if p_item[1] <= salary: #Determine whether you can afford 
                        shopping_list.append(p_item) 
                        salary -= p_item[1] 
                        print('Added %s into shopping car,your current balance is \033[31;1m%s\033[0m' %(p_item,salary)) 
                    else: 
                        print("\033[41; 1m, your balance is only [%s]\033[0m" % salary) 
                else: 
                    print('product_code [%s] is not excit'% user_choice) 
            elif user_choice == 'quit': 
                print('------shopping list-------')
                for i in shopping_list: 
                    print(i) 
                print('your current balance:%s' % salary) 
                exit() 
            else: 
                print('input true product_code,product_code is a number') 
            # break 
    else: 
        print('Please input correctly your salary')