Question

我正在尝试编写一个小计算器代码，因为我正在学习python。我的问题是，它始终在else语句中输出语法错误，因为我还是初学者，我不知道为什么。 :( Code of my calculator

Answer 1

您错过了colon : with else

应为else: {your logic}

Here's an example

更新：实际上你确实有结肠，但有条件。这应该是elif而不是else

将上次else更改为elif，如果没有默认检查，则您不一定需要其他内容。

Answer 2

您的代码实际上存在一些问题。

您不能在字符串和整数等之间进行转换。"4" + "5"不是9，而是"45"，因为它正在组合两个字符串。但如果你做int("4") + int("5")那么你会得到9.
在做else语句时，没有条件。

所以，基本的 if，elif，else 将是：

a = "yay"
if a == "yay":
    print("a likes you")
elif a == "no":
    print("a doesn't like you")
else:
    print("a doesn't want to respond")

Python 2.7

print ("Welcome to your friendly Python calculator.  Use + for addition and - for substraction")
print ("This code uses period (.) for decmimals")

first = "Please enter your first number "
second = "Please enter your second number "

operator = raw_input("Please choose an operation (+ or -) ")
if operator == "+":
    num1 = input(first)
    num2 = input(second)
    print ("Result: " + str(num1 + num2))
elif operator == "-":
    num1 = input(first)
    num2 = input(second)
    print ("Result: " + str(num1 - num2))
else:
    print("You didn't enter a valid operator.")

Python 3.6

print ("Welcome to your friendly Python calculator.  Use + for addition and - for substraction")
print ("This code uses period (.) for decmimals")

first = "Please enter your first number "
second = "Please enter your second number "

operator = input("Please choose an operation (+ or -) ")
if operator == "+":
    num1 = int(input(first))
    num2 = int(input(second))
    print ("Result: " + str(num1 + num2))
elif operator == "-":
    num1 = int(input(first))
    num2 = int(input(second))
    print ("Result: " + str(num1 - num2))
else:
    print("You didn't enter a valid operator.")

其他语句语法错误（简单计算器）

2 个答案: