将输出与预期值进行比较
在这一步中，你将学习如何将函数的输出与预期值进行比较。这是测试和确保函数正常工作的关键部分。通过将实际输出与预期输出进行比较，你可以识别并修复代码中的任何错误。
我们将继续使用前几步中的 calculate_sum.py 文件。如果你还未完成前几步，请创建包含以下内容的文件：
def calculate_sum(x, y):
"""
This function calculates the sum of two numbers.
If the sum is greater than 10, it returns double the sum.
"""
sum_result = x + y
if sum_result > 10:
return sum_result * 2
else:
return sum_result
## Example usage:
num1 = 10
num2 = 5
result = calculate_sum(num1, num2)
print("The sum of", num1, "and", num2, "is", result)
## Capture the output and perform an additional operation
final_result = result + 20
print("The final result after adding 20 is:", final_result)
num3 = 2
num4 = 3
result2 = calculate_sum(num3, num4)
print("The sum of", num3, "and", num4, "is", result2)
## Capture the output and perform an additional operation
final_result2 = result2 * 2
print("The final result after multiplying by 2 is:", final_result2)
现在，让我们添加一个函数来将输出与预期值进行比较，并打印一条消息，表明测试是通过还是失败。
-
在 VS Code 编辑器中打开 calculate_sum.py 文件。
-
按如下方式修改脚本：
def calculate_sum(x, y):
"""
This function calculates the sum of two numbers.
If the sum is greater than 10, it returns double the sum.
"""
sum_result = x + y
if sum_result > 10:
return sum_result * 2
else:
return sum_result
def compare_output(actual_output, expected_output):
"""
This function compares the actual output with the expected output.
"""
if actual_output == expected_output:
print("Test passed!")
else:
print("Test failed. Expected:", expected_output, "Actual:", actual_output)
## Example usage:
num1 = 10
num2 = 5
result = calculate_sum(num1, num2)
print("The sum of", num1, "and", num2, "is", result)
## Capture the output and perform an additional operation
final_result = result + 20
print("The final result after adding 20 is:", final_result)
## Compare the output with the expected value
expected_final_result = 50
compare_output(final_result, expected_final_result)
num3 = 2
num4 = 3
result2 = calculate_sum(num3, num4)
print("The sum of", num3, "and", num4, "is", result2)
## Capture the output and perform an additional operation
final_result2 = result2 * 2
print("The final result after multiplying by 2 is:", final_result2)
## Compare the output with the expected value
expected_final_result2 = 10
compare_output(final_result2, expected_final_result2)
在这个修改后的脚本中：
- 我们定义了一个名为
compare_output 的函数，它接受两个参数：actual_output 和 expected_output。
- 在函数内部，我们将
actual_output 与 expected_output 进行比较。
- 如果它们相等，我们打印 "Test passed!"。
- 如果它们不相等，我们打印 "Test failed." 以及预期值和实际值。
- 然后，我们使用
final_result 和 expected_final_result 调用 compare_output 函数，将第一次计算的输出与预期值 50 进行比较。
- 我们还使用
final_result2 和 expected_final_result2 调用 compare_output 函数，将第二次计算的输出与预期值 10 进行比较。
-
使用以下命令运行脚本：
python ~/project/calculate_sum.py
你应该会看到以下输出：
The sum of 10 and 5 is 30
The final result after adding 20 is: 50
Test passed!
The sum of 2 and 3 is 5
The final result after multiplying by 2 is: 10
Test passed!
这个输出表明，你可以成功地将函数的输出与预期值进行比较，并确定测试是通过还是失败。
