我正在尝试测试这个函数,该函数采用一个 Pandas 数据帧行,它用于进行保存到 csv 的 ftp 调用,打开该 csv 文件,对其进行格式化,并将其保存为泡菜。
我想测试以下内容:
修补 builtins.open 似乎不起作用,因为它被 to_pickle 间接调用,因此测试失败,因为 builtins.open 被调用两次。
测试功能:
def download_file(row):
path_from = row['source']
path_to_raw = LOCAL_RAW.format(row.name)
self.connection = FTP(self.url)
self.connection.login(self.username, self.password)
with open(path_to_raw, 'wb') as f:
self.connection.retrbinary('RETR ' + path_from, f.write)
self.connection.quit()
data = pd.read_csv(path_to_raw)
data.columns = ['a','b','c']
data.to_pickle(LOCAL_PKL.format(row.name))
单元测试:
import pandas as pd
import unittest.mock as mock
from unittest.mock import patch, mock_open, MagicMock, call
import maintain
@patch('builtins.open', create=True)
@patch('maintain.pd.read_csv')
def test_download_path(self, mock_open, mock_pd_read_csv):
mock_pd_read_csv.return_value = pd.DataFrame()
@mock.create_autospec
def mock_pd_to_pickle(self, path):
pass
with patch.object(pd.DataFrame, 'to_pickle', mock_pd_to_pickle):
real = maintain.DataFTP()
real.connection = MagicMock(name='connection')
row = pd.Series(data=['a','b'], index=['c','d'])
row.name = 'anything'
print(mock_open.assert_called_once_with(maintain.LOCAL_RAW.format(row.name), 'wb'))
print(mock_pd_to_pickle.assert_called_once_with(maintain.LOCAL_PKL.format(row.name)))
所以......这显然是错误的,但我不确定为什么。
此测试产生此错误:
AssertionError: Expected 'read_csv' to be called once. Called 0 times.
有没有人有任何建议或知道如何解决这个问题。
谢谢!
最佳答案
我终于得到了它的工作:
@patch('builtins.open', new_callable=mock_open)
@patch('maintain.pd.read_csv', return_value=pd.DataFrame())
@patch.object(pd.DataFrame, 'to_pickle')
def test_download_path(self, mock_to_pickle, mock_read_csv, mock_open):
real = maintain.EODDataFTP()
real.connection = mock.Mock(name='connection')
row = pd.Series(data=['','nyse'], index=['source','exchange'])
row.name = 'anything'
real.download_file(row)
mock_open.assert_called_once_with(maintain.LOCAL_RAW.format(row.name), 'wb')
mock_read_csv.assert_called_once()
mock_to_pickle.assert_called_once_with(maintain.LOCAL_PKL.format(row.name))
关于python - 如何模拟和测试 python open 和 pandas to_pickle,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54896732/