Python模擬庫不返回正確的模擬對象的'補丁'

Question

我試圖讓模擬庫返回一個特定的模擬對象與補丁。無論我嘗試什麼，如果我在'with'子句中實例化一個新對象，我會得到一個通用Mock對象，而不是我自定義的對象。

這是一個使用我的代碼記錄爲例：

import logging 

    my_mock = Mock() 
    my_mock.id = 'i-12341234' 

    with patch('logging.PlaceHolder', new=my_mock) as mockobj: 
     print mockobj.id   # correctly prints 'i-12341234' 

     newobj = logging.PlaceHolder(None) 
     print newobj.id   # prints <Mock name='mock().id' id='47607184'> 

我怎樣才能模擬每logging.Placeholder的新實例被實例化時my_mock回報？

事實證明，繼承Mock並使用new_callable工作傳遞它。由於我花時間試圖讓版本達到上述工作狀態，所以我仍然感激並回答。

Answer 1

import logging 
from mock import Mock, patch 

my_mock = Mock() 
my_mock.id = 'i-12341234' 

with patch('logging.PlaceHolder', new=my_mock) as mockobj: 
    mockobj.return_value = mockobj # <-- added this line. 
    print mockobj.id 
    newobj = logging.PlaceHolder(None) 
    print newobj.id 

替代

import logging 
from mock import Mock, patch 

my_mock = Mock() 
my_mock.id = 'i-12341234' 
my_mock.return_value = my_mock # <--- 

with patch('logging.PlaceHolder', new=my_mock) as mockobj: 
    assert mockobj.id == 'i-12341234' 
    newobj = logging.PlaceHolder(None) 
    assert newobj.id == 'i-12341234'