Pytest：如何定位 FutureWarning 並修復它？

Question

在我當前的項目中，當我運行測試（使用pytest ）時，我得到了這個 output （除其他外）：

ml_framework/tests/test_impute.py: 8 warnings
ml_framework/tests/test_transform_pipeline.py: 9 warnings
ml_framework/tests/test_data_transforms.py: 27 warnings
ml_framework/tests/test_jsonizer.py: 4 warnings
  /home/sondracek/anaconda3/envs/p3.8/lib/python3.8/site-packages/sklearn/utils/validation.py:70: FutureWarning: Pass standardize=False as keyword args. From version 1.0 (renaming of 0.25) passing these as positional arguments will result in an error
    warnings.warn(f"Pass {args_msg} as keyword args. From version "

這個FutureWarning非常清楚——從 1.0 版（我目前使用0.24 ）開始，一些參數將發生變化，我將無法將standardize作為位置 arguments 傳遞。

但問題是 -我怎樣才能找到我應該在哪里將此位置參數更改為關鍵字？

我可以 go 到警告 output 中提到的validation.py ，但是有一般_deprecate_positional_args function 不告訴我哪個代碼調用它。

在這種特殊情況下，我猜這將來自從我的代碼中使用的sklearn.preprocessing導入的PowerTransformer ，具有standardize參數並在列出的測試中進行了測試。 是否有一種通用方法可以輕松找到任何FutureWarning的原因？ 還是我需要檢查所有代碼並嘗試以某種方式找到它？

Answer 1

Pytest 讓您將FutureWarning作為錯誤引發，這樣它指向引發警告的代碼位置，最簡單的方法是通過警告標志

pytest -W error::FutureWarning test_script.py

或通過pytestmark在test_script.py中

pytestmark = pytest.mark.filterwarnings("error::FutureWarning")

您可以在此處和 此處閱讀有關指定對警告采取的操作的更多信息。

例子

考慮以下虛擬示例test_transform.py腳本

# test_transform.py
import pytest


pytestmark = pytest.mark.filterwarnings("error::FutureWarning")


def test_transformer_boxcox():

    from sklearn.preprocessing import PowerTransformer
    
    pt = PowerTransformer('box-cox', False)
    
    assert True
    

def test_transformer_yeo_johnson():

    from sklearn.preprocessing import PowerTransformer
    
    pt = PowerTransformer('yeo-johnson', False)
    
    assert True

並在終端上運行

pytest test_transform.py > logs.log

日志准確地告訴我PowerTransformer引發了FutureWarning 。

===================================================== test session starts =====================================================
platform linux -- Python 3.7.6, pytest-6.2.2, py-1.10.0, pluggy-0.13.1
rootdir: /home/jovyan/work
collected 2 items

test_transform.py FF                                                                                                    [100%]

========================================================== FAILURES ===========================================================
___________________________________________________ test_transformer_boxcox ___________________________________________________

    def test_transformer_boxcox():
    
        from sklearn.preprocessing import PowerTransformer
    
>       pt = PowerTransformer('box-cox', False)

test_transform.py:11: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

args = (<[AttributeError("'PowerTransformer' object has no attribute 'copy'") raised in repr()] PowerTransformer object at 0x7fa0bda14d50>, 'box-cox', False)
kwargs = {}, extra_args = 1, args_msg = 'standardize=False'

    @wraps(f)
    def inner_f(*args, **kwargs):
        extra_args = len(args) - len(all_args)
        if extra_args <= 0:
            return f(*args, **kwargs)
    
        # extra_args > 0
        args_msg = ['{}={}'.format(name, arg)
                    for name, arg in zip(kwonly_args[:extra_args],
                                         args[-extra_args:])]
        args_msg = ", ".join(args_msg)
        warnings.warn(f"Pass {args_msg} as keyword args. From version "
                      f"{version} passing these as positional arguments "
>                     "will result in an error", FutureWarning)
E       FutureWarning: Pass standardize=False as keyword args. From version 1.0 (renaming of 0.25) passing these as positional arguments will result in an error

/opt/conda/lib/python3.7/site-packages/sklearn/utils/validation.py:72: FutureWarning
________________________________________________ test_transformer_yeo_johnson _________________________________________________

    def test_transformer_yeo_johnson():
    
        from sklearn.preprocessing import PowerTransformer
    
>       pt = PowerTransformer('yeo-johnson', False)

test_transform.py:20: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

args = (<[AttributeError("'PowerTransformer' object has no attribute 'copy'") raised in repr()] PowerTransformer object at 0x7fa0bd02f750>, 'yeo-johnson', False)
kwargs = {}, extra_args = 1, args_msg = 'standardize=False'

    @wraps(f)
    def inner_f(*args, **kwargs):
        extra_args = len(args) - len(all_args)
        if extra_args <= 0:
            return f(*args, **kwargs)
    
        # extra_args > 0
        args_msg = ['{}={}'.format(name, arg)
                    for name, arg in zip(kwonly_args[:extra_args],
                                         args[-extra_args:])]
        args_msg = ", ".join(args_msg)
        warnings.warn(f"Pass {args_msg} as keyword args. From version "
                      f"{version} passing these as positional arguments "
>                     "will result in an error", FutureWarning)
E       FutureWarning: Pass standardize=False as keyword args. From version 1.0 (renaming of 0.25) passing these as positional arguments will result in an error

/opt/conda/lib/python3.7/site-packages/sklearn/utils/validation.py:72: FutureWarning
=================================================== short test summary info ===================================================
FAILED test_transform.py::test_transformer_boxcox - FutureWarning: Pass standardize=False as keyword args. From version 1.0 ...
FAILED test_transform.py::test_transformer_yeo_johnson - FutureWarning: Pass standardize=False as keyword args. From version...
====================================================== 2 failed in 0.71s ======================================================