Python Mock 多次调用，结果不同
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Python Mock Multiple Calls with Different Results
提问by FearlessFuture
I want to be able to have multiple calls to a particular attribute function return a different result for each successive call.
我希望能够对特定属性函数进行多次调用，每次连续调用都返回不同的结果。
In the below example, I would like increment to return 5 on its first call and then 10 on its second call.
在下面的示例中，我希望 increment 在第一次调用时返回 5，然后在第二次调用时返回 10。
Ex:
前任：
import mock
class A:
def __init__(self):
self.size = 0
def increment(self, amount):
self.size += amount
return amount
@mock.patch("A.increment")
def test_method(self, mock_increment):
def diff_inc(*args):
def next_inc(*args):
#I don't know what belongs in __some_obj__
some_obj.side_effect = next_inc
return 10
return 5
mock_increment.side_effect = diff_inc
The below page has almost everything that I need except that it assumes that the caller would be an object named "mock", but this can't be assumed.
下面的页面几乎包含了我需要的所有内容，只是它假定调用者是一个名为“mock”的对象，但这不能被假定。
http://mock.readthedocs.org/en/latest/examples.html#multiple-calls-with-different-effects
http://mock.readthedocs.org/en/latest/examples.html#multiple-calls-with-different-effects
采纳答案by Silfheed
You can just pass an iterable to side effect and have it iterate through the list of values for each call you make.
您可以将迭代传递给副作用，并让它遍历您进行的每个调用的值列表。
@mock.patch("A.increment")
def test_method(self, mock_increment):
mock_increment.side_effect = [5,10]
self.assertEqual(mock_increment(), 5)
self.assertEqual(mock_increment(), 10)
回答by Nate Brennand
I think the popping values off of a list method will be more straightforward. The below example works for the test you wanted to perform.
我认为从列表方法中弹出值会更直接。以下示例适用于您要执行的测试。
Also, I've had a difficult time with the mock library before and have found that the mock.patch.object()method was typically easier to use.
此外，我之前在使用模拟库时遇到了困难，并且发现该mock.patch.object()方法通常更易于使用。
import unittest
import mock
class A:
def __init__(self):
self.size = 0
def increment(self, amount):
self.size += amount
return amount
incr_return_values = [5, 10]
def square_func(*args):
return incr_return_values.pop(0)
class TestMock(unittest.TestCase):
@mock.patch.object(A, 'increment')
def test_mock(self, A):
A.increment.side_effect = square_func
self.assertEqual(A.increment(1), 5)
self.assertEqual(A.increment(-20), 10)
