pandas.errors.PerformanceWarning

异常 pandas.errors。性能警告

当可能影响性能时发出警告。

例子

>>> df = pd.DataFrame({"jim": [0, 0, 1, 1],
...                    "joe": ["x", "x", "z", "y"],
...                    "jolie": [1, 2, 3, 4]})
>>> df = df.set_index(["jim", "joe"])
>>> df
          jolie
jim  joe
0    x    1
     x    2
1    z    3
     y    4
>>> df.loc[(1, 'z')]  
# PerformanceWarning: indexing past lexsort depth may impact performance.
df.loc[(1, 'z')]
          jolie
jim  joe
1    z        3