我在DataFrame 中使用了 pd.to_period,所以它的索引变成了 Pandas period 类型(类型’pandas._period.Period’)。 现在,我想将该索引转换为字符串。我正在尝试应用以下内容: df.index=df.index.astype(str) 然而这不起作用… ValueError: Cannot cast PeriodIndex to dtype |S0 从那时起我的代码就被冻结了。
dtype: datetime64[ns] In [566]: store.select_column("df_dc", "string") Out[566]: 0 foo 1 foo 2 foo 3 foo 4 NaN 5 NaN 6 foo 7 bar Name: string, dtype: object
copy, raise_on_error,values, klass, mgr,**kwargs)502503# _astype_nansafe works finewith1-donly--> 504 values = _astype_nansafe(values.ravel(), dtype, copy=True)505values=values.reshape(self.shape)506C:\Anaconda3\lib\site-packages\pandas\types\cast.pyin_astype_nansafe(arr, dtype,copy...
Polars 使用 Arrow 在内存中管理数据,并依赖于 Rust 实现中的计算核心 来执行转换。类型转换通过 cast 方法实现。 cast 方法包括一个 strict 参数,该参数确定当 Polars 遇到无法从源 DataType 转换为目标 DataType 的值时的行为。默认情况下,strict=True,这意味着 Polars 将引发错误,通知用户转换失败,并提供无法转...
column labelanddtypeisa numpy.dtypeorPython type to cast oneormore of the DataFrame's columns to column-specific types.errors : {'raise','ignore'}, default'raise'. Control raising of exceptions on invalid dataforprovided dtype.- ``raise`` : allow exceptions to be raised- ``ignore`` : ...
DataFrame.applymap(func)Apply a function to a DataFrame that is intended to operate elementwise, i.e. DataFrame.aggregate(func[, axis])Aggregate using callable, string, dict, or list of string/callables DataFrame.transform(func, *args, **kwargs)Call function producing a like-indexed NDFrame ...
使用CAST() 或 CONVERT() 函数。 示例: sql SELECT CAST(price AS INT) FROM products; -- 将价格转换为整数 数据迁移工具: 如Apache NiFi、Talend,用于不同数据库或文件格式之间的数据转换。 5. 批量文件转换 命令行工具: FFmpeg(视频/音频转换): ...
to_string([buf, columns,…]) #Render a DataFrame to a console-friendly tabular output. DataFrame.to_clipboard([excel, sep]) #Attempt to write text representation of object to the system clipboard This can be pasted into Excel, for example. 总结 DataFrame是二维数组的处理,例如,我们在图像操作...
Convert String to Integer You can use PandasSeries.astype()to convert or cast a string to an integer in a specific DataFrame column or Series. Given that each column in a DataFrame is essentially a Pandas Series, accessing a specific column from the DataFrame yields a Series object. For inst...
(), dtype, copy=True) 505 values = values.reshape(self.shape) 506 C:\Anaconda3\lib\site-packages\pandas\types\cast.py in _astype_nansafe(arr, dtype, copy) 535 536 if copy: --> 537 return arr.astype(dtype) 538 return arr.view(dtype) 539 ValueError: could not convert string to ...