Python输入问题？

因此，这段代码给我带来了一些麻烦，在启动代码时，一切正常，它要求我输入一个命令，如果我输入“help”，它会完全执行它应该执行的操作，即列出所有命令，然后应该通过start（）命令重置，并再次要求我输入一个命令，但是这次无论我写什么，它都会激活这段代码：

谁能帮我解决这个问题，或者解释一下为什么会发生这种情况

---

感谢您的高级支持。

您必须在此处使用while循环，而且

repr（i）

比

““+i+””更有效。

：

示例输出：

name_list = []
command_list = ["Add" ,"Help"]

def start():
    return input("Hello please type in a command : ")

a=start()

while a.lower()=='help':
    print("Here are the following commands for this program : ")
    i = 0
    for i in command_list :
       print(repr(i))
    a=start()


if a.lower()=='add':
 name = input("Insert name please : ")
 print("Welcome " + name)
 name_list.append(name)
else:
 print('invalid input')

而且：

Hello please type in a command : help
Here are the following commands for this program : 
'Add'
'Help'
Hello please type in a command : Help
Here are the following commands for this program : 
'Add'
'Help'
Hello please type in a command : Add
Insert name please : Bob
Welcome Bob

返回：

print(name_list)

---

您的代码有几个问题。这是一个有效的版本

['Bob']

您问题的解决方案：

if (input == "Add" or "add" ):
 name = input("Insert name please : ")
 print("Welcome " + name)
 name_list.append(name)

---

您可能需要一段时间的循环somewhere@AshishAcharya什么的while循环？如果一个答案解决了你的问题，请先接受它。你的

If

语句将始终为真。这不是你想要的情况。还有

repr（i）

比

““+i+””更高效。

还有

repr（i）

比

“+i+”更高效。

['Bob']

name_list = []
command_list = ["Add", "Help"]


def start():
    return input("Hello please type in a command : ")


name = ""

while not name:
    command = start()

    if (command.lower() == "add"):
        name = input("Insert name please : ")
        print("Welcome " + name)
        name_list.append(name)

    # printing help for everything except add
    else:
        print("Here are the following commands for this program : ")
        i = 0
        for i in command_list:
            print(repr(i))

if (input == "help" or "Help"):
    print("Here are the following commands for this program : ")
    i = 0
    for i in command_list :
       print("'" + i + "'")
    start()  # <--- your call to start() function does not reset where the interpreter left off reading you code.

if (input == "Add" or "add" ):
 name = input("Insert name please : ")
 print("Welcome " + name)
 name_list.append(name)

name_list = []
command_list = ["Add" ,"Help"]

def start():
 input("Hello please type in a command : ")
while True:
   start()

   if (input == "help" or "Help"):
       print("Here are the following commands for this program : ")
       i = 0
       for i in command_list :
          repr(i)

   if (input == "Add" or "add" ):
    name = input("Insert name please : ")
    print("Welcome " + name)
    name_list.append(name)

   if input == "something for break condition":
       break

name_list = []
command_list = ["Add" ,"Help"]

def start():
 inpt =  input("Hello please type in a command : ")
 if (inpt == "help" or inpt == "Help"):
    print("Here are the following commands for this program : ")
    print(command_list)
    start()
 elif (inpt == "Add" or inpt == "add" ):
     name = input("Insert name please : ")
     print("Welcome " + name)
     name_list.append(name)
     yn = input("Do you want to add another person? ")
     if yn in ['y','Y','yes','Yes','YES']:
         start()
     else: 
         print ("Quitting!! all the people entered are")
         print(name_list)
         return (None)

 else:
     print("Please type 'help' for help")
     start()