我尝试开发python比较器。我的变量名为:compare_type
有问题,我想将其设置为l-left join / r - right join / b - inner join (both)
如果我设置了compare_type = 'l';
,所有的工作都很好
然而,当我执行compare_type = 'r';
或compare_type = 'b';
十次时,我得到了以下错误:
raise KeyError(key) from err
KeyError: 'both'
或
raise KeyError(key) from err
KeyError: 'right_only'
我做错了什么
完整代码:
import pandas as pd
col_to_compare = 0;
compare_type = 'r'; #l-left join / r - right join / b - inner join (both)
file1_df = pd.read_csv('filename1.csv', usecols=[col_to_compare], names=[col_to_compare])
file2_df = pd.read_csv('filename2.csv', usecols=[col_to_compare], names=[col_to_compare])
file1_df[col_to_compare] = file1_df[col_to_compare].str.upper()
file2_df[col_to_compare] = file2_df[col_to_compare].str.upper()
comparison_result = pd.merge(file1_df, file2_df, on=col_to_compare,
how='left' if (compare_type == 'l') else 'right' if (compare_type == 'r') else 'inner',
indicator=True)
comparison_result = comparison_result.loc[comparison_result['_merge'] == 'left_only' if (compare_type == 'l') else 'right_only' if (compare_type == 'r') else 'both']
print(comparison_result)
comparison_result.to_csv('result.csv')
完全回溯:
C:\Users\john\PycharmProjects\L1\venv\Scripts\python.exe C:/Users/john/PycharmProjects/L1/CsvComparer/csv_comparer.py
Traceback (most recent call last):
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\indexes\base.py", line 3361, in get_loc
return self._engine.get_loc(casted_key)
File "pandas\_libs\index.pyx", line 76, in pandas._libs.index.IndexEngine.get_loc
File "pandas\_libs\index_class_helper.pxi", line 105, in pandas._libs.index.Int64Engine._check_type
File "pandas\_libs\index_class_helper.pxi", line 105, in pandas._libs.index.Int64Engine._check_type
KeyError: 'right_only'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "C:/Users/john/PycharmProjects/L1/CsvComparer/csv_comparer.py", line 29, in <module>
comparison_result = comparison_result.loc[comparison_result['_merge'] == 'left_only' if (compare_type == 'l') else 'right_only' if (compare_type == 'r') else 'both']
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\indexing.py", line 931, in __getitem__
return self._getitem_axis(maybe_callable, axis=axis)
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\indexing.py", line 1164, in _getitem_axis
return self._get_label(key, axis=axis)
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\indexing.py", line 1113, in _get_label
return self.obj.xs(label, axis=axis)
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\generic.py", line 3776, in xs
loc = index.get_loc(key)
File "C:\Users\john\PycharmProjects\L1\venv\lib\site-packages\pandas\core\indexes\base.py", line 3363, in get_loc
raise KeyError(key) from err
KeyError: 'right_only'
Process finished with exit code 1
这只是链式不等式和if运算符中的一个问题
按以下顺序计算:
当
compare_type
为'r'
时,if语句将生成整个条件,从而导致:这就是为什么你会有钥匙错误
使用括号阐明您想要的操作顺序,或者更好地定义一个更易于阅读的变量。在这种情况下:
您对以下行有异议:
我的工作代码:
输出
compare_type = 'r'
:输出
compare_type = 'l'
:输出
compare_type = 'b'
:注:
相关问题 更多 >
编程相关推荐