关于python：未定义变量”result”


Variable “result” is not defined

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我一直在研究这段代码，每次运行它时，它都会说结果没有定义。

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Error: Traceback (most recent call last):
  File"/Users/Bubba/Documents/Jamison's School Work/Programming/Python scripts/Ch9Lab2.py", line 24, in <module>
    print(str(numberOne) +"" + operation +"" + str(numberTwo) +" =" + str(result))
NameError: name 'result' is not defined

原代码：

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def performOperation(numberOne, numberTwo):
    if operation =="+":
        result = numberOne + numberTwo
    if operation =="-":
        result = numberOne - numberTwo
    if operation =="*":
        result = numberOne * numberTwo
    if operation =="/":
        result = numberOne / numberTwo

numberOne = int(input("Enter the first number:"))
numberTwo = int(input("Enter the second number:"))
operation = input("Enter an operator (+ - * /):")

performOperation(numberOne, numberTwo)

print(str(numberOne) +"" + operation +"" + str(numberTwo) +" =" + str(result))
相关讨论

您需要使用return关键字在函数外部使用变量结果。

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def performOperation(numberOne, numberTwo):
    ...
    return result

result = performOperation(numberOne, numberTwo)

变量'result'只在函数的作用域中定义。如果要打印出来，则应将PerformOperation函数的结果赋给结果变量。另外，确保在函数中实际返回了一些内容。

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def performOperation(numberOne, numberTwo):
    if operation =="+":
        result = numberOne + numberTwo
    if operation =="-":
        result = numberOne - numberTwo
    if operation =="*":
        result = numberOne * numberTwo
    if operation =="/":
        result = numberOne / numberTwo
    return result

result = performOperation(numberOne, numberTwo)
print str(result) # will print the result