Question

def name_hi(x):
    if type(x)!= <type 'str'> :
        print "Invaild answer,Try again"
    else:
        print "Hello"+ x
name_hi(raw_input("what's your name?"))

如何确保我得到的答案是字符串？

Answer 1

您正在寻找：

if type(x) == str:

或者，更好的是：

if isinstance(x, str):

那就是说，raw_input()只会返回一个字符串。它不会返回任何其他内容。

由于您正在尝试检查字符串是否只包含字母，因此您应该拨打isalpha()：

if x.isalpha():

整合：

def name_hi(x):
    if x.isalpha():
        print "Hello, " + x + "."
    else:
        print "Invalid answer; try again."

name_hi(raw_input("What's your name?"))

Answer 2

你想要isinstance（）

def check(x)
    return isinstance(x, str)

Answer 3

检查类型是否脆弱。只是尝试做你想做的事情并看看它是否有效可能会更好：

    Dim TextSearch As String =
        "PrinterName : PDFCreator()" + vbCrLf +
        "PortName: PDFCreator()" + vbCrLf +
        "Status: Unknown()" + vbCrLf +
        "DriverName: PDFCreator()" + vbCrLf +
        "PrinterName: Lexmark E360dn XL" + vbCrLf +
        "PortName: someport()" + vbCrLf +
        "Status: Unknown()" + vbCrLf +
        "DriverName: Lexmark E360dn XL" + vbCrLf +
        "HostAddress: somehostaddress()"

    Dim printers = From printer In TextSearch.Split(vbCrLf.ToCharArray)
                   Where printer.ToLower.StartsWith("printername")
                   Select printer.Split(":").Last
    For Each printer As String In printers
        Debug.Print(printer)
    Next

那样：

def name_hi(x):
    try:
        print "Hello"+ x
    except TypeError:
        print "Invaild answer,Try again"

我如何只在Python中想要的数据类型中做出答案？

3 个答案: