检查用户inpu的长度

Question

我试图检查用户输入的字符串的长度，如果它的<；5通过，不管它仍然通过我的try except语句的长度是多少

打印“ 请输入公司的股票代号 你想看谁的最后收盘价

while True:
   symbol = raw_input("Enter Stock Symbol: ")
   try:
      len(symbol) < 5
      break

   except ValueError:
      print 'Greater than 4 characters, Try again'

print 'Great your stock symbol is less than 5'

Answer 1

你不需要尝试/除了：

while True:
   symbol = raw_input("Enter Stock Symbol: ")
   if len(symbol) > 4:       
      print 'Greater than 4 characters, Try again'
   else:
       print 'Great your stock symbol {} is less than 5'.format(symbol)
       break


In [3]: paste
while True:
   symbol = raw_input("Enter Stock Symbol: ")
   if len(symbol) > 4:       
      print 'Greater than 4 characters, Try again'
   else:
       print 'Great your stock symbol {} is less than 5'.format(symbol)
       break

## -- End pasted text --
Enter Stock Symbol: FOOBAR
Greater than 4 characters, Try again
Enter Stock Symbol: YHOO
Great your stock symbol YHOO is less than 5

在你的代码中：

try:
    len(symbol) < 5 # always checks len
    break # always breaks
except ValueError:

例如，如果您希望将输入强制转换为捕获一个值错误的int，则可以使用try/except，但它不适用于您的情况。