python进阶版Cucumber示例

以下是一个简单的Python进阶版Cucumber示例：

假设我们要测试一个简单的计算器程序，它能够执行加、减、乘、除四种基本运算。我们可以使用Python的unittest模块来编写测试用例，并使用Behave框架来编写BDD测试。

首先，我们需要安装Behave框架：

pip install behave

然后，我们可以编写.feature文件，描述我们要测试的场景：

Feature: Calculator

  Scenario: Addition
    Given I have entered 10 into the calculator
    And I have entered 5 into the calculator
    When I press add
    Then the result should be 15 on the screen

  Scenario: Subtraction
    Given I have entered 10 into the calculator
    And I have entered 5 into the calculator
    When I press subtract
    Then the result should be 5 on the screen

  Scenario: Multiplication
    Given I have entered 10 into the calculator
    And I have entered 5 into the calculator
    When I press multiply
    Then the result should be 50 on the screen

  Scenario: Division
    Given I have entered 10 into the calculator
    And I have entered 5 into the calculator
    When I press divide
    Then the result should be 2 on the screen

接下来，我们可以编写.steps文件，实现.feature文件中描述的步骤：

from behave import given, when, then
from calculator import Calculator

@given('I have entered {num:d} into the calculator')
def step_impl(context, num):
    context.calc = Calculator()
    context.calc.enter(num)

@when('I press add')
def step_impl(context):
    context.calc.add()

@when('I press subtract')
def step_impl(context):
    context.calc.subtract()

@when('I press multiply')
def step_impl(context):
    context.calc.multiply()

@when('I press divide')
def step_impl(context):
    context.calc.divide()

@then('the result should be {result:d} on the screen')
def step_impl(context, result):
    assert context.calc.result == result

最后，我们可以编写一个Calculator类来实现计算器的基本功能：

class Calculator:
    def __init__(self):
        self.result = 0

    def enter(self, num):
        self.result = num

    def add(self):
        self.result += self.current

    def subtract(self):
        self.result -= self.current

    def multiply(self):
        self.result *= self.current

    def divide(self):
        self.result /= self.current

现在，我们可以在终端中执行以下命令来运行测试：

behave calculator.feature

这将运行.feature文件中描述的所有场景，并报告测试结果。

这是一个简单的Python进阶版Cucumber示例，演示了如何使用Behave框架编写BDD测试用例。