如何在while循环python中切换函数
我正在尝试制作一个程序,可以添加、删除和查看用户输入的菜肴。这看起来很简单,但是,我的while循环遇到了问题。当我键入add时,我可以将项目添加到列表中,但是,当我键入view时,addDish函数会继续循环。我想我用if语句修复了它,但是缺少了一些东西如何在while循环python中切换函数,python,Python,我正在尝试制作一个程序,可以添加、删除和查看用户输入的菜肴。这看起来很简单,但是,我的while循环遇到了问题。当我键入add时,我可以将项目添加到列表中,但是,当我键入view时,addDish函数会继续循环。我想我用if语句修复了它,但是缺少了一些东西 dish_list = [] user_input = '' def addDish(dish_list): user_input = input("Please type the dish you want: ")
dish_list = []
user_input = ''
def addDish(dish_list):
user_input = input("Please type the dish you want: ")
dish_list.append(user_input)
#def deleteDish(dish_list):
def viewDish(dish_list):
for i in range(len(dish_list)):
print(dish_list[i])
user_input = input("Please enter a command: ")
while True:
if user_input == '':
user_input = input("Please enter a command: ")
elif user_input == 'add':
addDish(dish_list, user_input)
elif user_input == 'view':
viewDish(dish_list)
您不应该使用while循环,而应该调用一个函数,该函数在处理之前的输入后请求用户输入
dish_list = []
def addDish(dish_list):
user_input = input("Please type the dish you want: ")
dish_list.append(user_input)
#def deleteDish(dish_list):
def viewDish(dish_list):
for i in range(len(dish_list)):
print(dish_list[i])
def get_input():
user_input = input("Please enter a command: ")
if user_input == 'add':
addDish(dish_list, user_input)
elif user_input == 'view':
viewDish(dish_list)
getInput()
getInput()
稍微干净一点:
dish_list = []
def add_dish(dish_list):
user_input = input("Please type the dish you want: ")
dish_list.append(user_input)
def view_dish(dish_list):
# for dish in dish_list:
# print(dish)
print('\n'.join(dish_list))
while True:
user_input = input("Please enter a command: ")
if user_input == 'add':
add_dish(dish_list)
elif user_input == 'view':
view_dish(dish_list)
else:
print("Unknown command %s" % user_input)
您的变量user_input永远不会设置回空,因此您永远无法输入新命令,因为它只将您输入的最后一个条目作为user_input,这将是addDish函数中读取的dish类型。此外,您对addDish的调用还有一个额外的参数。我还建议将所有内容都放到main方法中
def addDish(dish_list):
user_input = input("Please type the dish you want: ")
dish_list.append(user_input)
def viewDish(dish_list):
for i in range(len(dish_list)):
print(dish_list[i])
def main():
dish_list = []
while True:
user_input = ''
if user_input == '':
user_input = input("Please enter a command: ")
elif user_input == 'add':
addDish(dish_list)
elif user_input == 'view':
viewDish(dish_list)
main()
以下是上述代码片段的固定版本:
def addDish(dish_list):
user_input = raw_input("Please type the dish you want: ")
dish_list.append(user_input)
#def deleteDish(dish_list):
def viewDish(dish_list):
for dish in dish_list:
print(dish)
dish_list = []
while True:
user_input = raw_input("Please enter a command: ")
if user_input == 'add':
addDish(dish_list)
elif user_input == 'view':
viewDish(dish_list)
elif user_input == 'exit':
print('Over!')
break
else:
print('Wrong entry. Retry...')
执行输出:
$python so.py
Please enter a command: add
Please type the dish you want: Bread
Please enter a command: add
Please type the dish you want: Burger
Please enter a command: view
Bread
Burger
Please enter a command: foo
Wrong entry. Retry...
Please enter a command: exit
Over!
$
只要您循环一次,
user\u input
就不再等于'
,因此您的第一个条件将不会再次触发,而是会触发您在第一次迭代中设置的user\u input
,您还需要正确调用addDish
,删除user\u input
参数。