如何让变量同时接收字符串和整数？

Question

这是我的代码，但它不适用于 python 3.4

print ("Hello")

b = str(input("Where do you go?\n"))

def place(a):
    if a == "r" or a > 0:
        print("Turned right.")
    elif a == "l" or a < 0:
        print("Turned left.")
    else:
        print("Invalid")
        a = int(str(input("Where do you go?\n")))
        place(a)

place(b)

我想让 'b' 成为一个 int 或一个字符串

Answer 1

使用try except块：

b = input("Where do you go?\n")

def place(a):
    try:
        a = int(a)
        # code for a being a number
    except ValueError:
        # a is a letter

Answer 2

isdigit() 方法会告诉你一个字符串是否是一个整数。

a = "1"
if a.isdigit():
    a = int(a)

Answer 3

这不是你想要的吗？

def place(a):
    try:
        b = int(a)
    except ValueError:
        b = 0

    if (b != 0):
        if b > 0:
            print("Turned right.")
        else:
            print("Turned left.")
    elif (type(a) is str) and ((a == 'r') | (a == 'l')):
        if a == 'r':
            print("Turned right.")
        else:
            print("Turned Left")
    else:
        print("Invalid")
        raise TypeError("Nothing to do")