如何限制字符串中的字母数量

Question

I have a program that asks a the user to input a question, the program then answers it. What I want to know is how do I limit the amount of letters a user can input into a variable.

Answer 1

Python's input function cannot do this directly; but you can truncate the returned string, or repeat until the result is short enough.

# method 1
answer = input("What's up, doc? ")[:10]  # no more than 10 characters

# method 2
while True:
    answer = input("What's up, doc? ")
    if len(answer) <= 10:
        break
    else:
        print("Too much info - keep it shorter!")

If that's not what you're asking, you need to make your question more specific.

Answer 2

您只能获得输入文本的前n个字符，如下所示：

data = raw_input()[:10]

Answer 3

use this:

while True:
    answer = input("What's up, doc? ")
    if len(answer) >= 10:
        print("Too much info - keep it shorter!")

Answer 4

You can check it with builtin len function:

my_input = raw_input("Enter something ")
if len(my_input) > 3:
  print "More then 3"
else:
  print "Ok"