将numpy.ndarray写入excel

引言

　　很多情况下，我们可以将数据结果保存到txt文件中便于后续查看或者再处理，然而为了进行汇报、论文撰写等工作，我们将数据放入表格，为后续整理会提供极大的便利。我们可以利用pandas库进行numpy.ndarray数据保存到excel。

函数说明

pandas.DataFrame.to_excel

DataFrame.to_excel(self, excel_writer, sheet_name='Sheet1', na_rep='', float_format=None, columns=None, header=True, index=True, index_label=None, startrow=0, startcol=0, engine=None, merge_cells=True, encoding=None, inf_rep='inf', verbose=True, freeze_panes=None)[source]

Write object to an Excel sheet.

To write a single object to an Excel .xlsx file it is only necessary to specify a target file name. To write to multiple sheets it is necessary to create an ExcelWriter object with a target file name, and specify a sheet in the file to write to.

Multiple sheets may be written to by specifying unique sheet_name. With all data written to the file it is necessary to save the changes. Note that creating an ExcelWriter object with a file name that already exists will result in the contents of the existing file being erased.

Parameters:

Parameters:	excel_writer : str or ExcelWriter object File path or existing ExcelWriter. sheet_name : str, default ‘Sheet1’ Name of sheet which will contain DataFrame. na_rep : str, default ‘’ Missing data representation. float_format : str, optional Format string for floating point numbers. For example `float_format="%.2f"` will format 0.1234 to 0.12. columns : sequence or list of str, optional Columns to write. header : bool or list of str, default True Write out the column names. If a list of string is given it is assumed to be aliases for the column names. index : bool, default True Write row names (index). index_label : str or sequence, optional Column label for index column(s) if desired. If not specified, and header and indexare True, then the index names are used. A sequence should be given if the DataFrame uses MultiIndex. startrow : int, default 0 Upper left cell row to dump data frame. startcol : int, default 0 Upper left cell column to dump data frame. engine : str, optional Write engine to use, ‘openpyxl’ or ‘xlsxwriter’. You can also set this via the options `io.excel.xlsx.writer`, `io.excel.xls.writer`, and `io.excel.xlsm.writer`. merge_cells : bool, default True Write MultiIndex and Hierarchical Rows as merged cells. encoding : str, optional Encoding of the resulting excel file. Only necessary for xlwt, other writers support unicode natively. inf_rep : str, default ‘inf’ Representation for infinity (there is no native representation for infinity in Excel). verbose : bool, default True Display more information in the error logs. freeze_panes : tuple of int (length 2), optional Specifies the one-based bottommost row and rightmost column that is to be frozen. New in version 0.20.0..

excel_writer : str or ExcelWriter object: File path or existing ExcelWriter.
sheet_name : str, default ‘Sheet1’: Name of sheet which will contain DataFrame.
na_rep : str, default ‘’: Missing data representation.
float_format : str, optional: Format string for floating point numbers. For example float_format="%.2f" will format 0.1234 to 0.12.
columns : sequence or list of str, optional: Columns to write.
header : bool or list of str, default True: Write out the column names. If a list of string is given it is assumed to be aliases for the column names.
index : bool, default True: Write row names (index).
index_label : str or sequence, optional: Column label for index column(s) if desired. If not specified, and header and indexare True, then the index names are used. A sequence should be given if the DataFrame uses MultiIndex.
startrow : int, default 0: Upper left cell row to dump data frame.
startcol : int, default 0: Upper left cell column to dump data frame.
engine : str, optional: Write engine to use, ‘openpyxl’ or ‘xlsxwriter’. You can also set this via the options io.excel.xlsx.writer, io.excel.xls.writer, and io.excel.xlsm.writer.
merge_cells : bool, default True: Write MultiIndex and Hierarchical Rows as merged cells.
encoding : str, optional: Encoding of the resulting excel file. Only necessary for xlwt, other writers support unicode natively.
inf_rep : str, default ‘inf’: Representation for infinity (there is no native representation for infinity in Excel).
verbose : bool, default True: Display more information in the error logs.
freeze_panes : tuple of int (length 2), optional: Specifies the one-based bottommost row and rightmost column that is to be frozen.

New in version 0.20.0..

例子

 1 import numpy as np
 2 import pandas as pd 
 3 
 4 data = np.random.randn(2, 3).astype(np.float32)
 5 dataFrame = pd.DataFrame(data, 
 6                         index=['row 1', 'row 2'],
 7                         columns=['col 1', 'col 2', 'col 3']) # 说明行和列的索引名
 8 
 9 dataFrame2 = dataFrame.copy()
10 
11 with pd.ExcelWriter('test.xlsx') as writer: # 一个excel写入多页数据
12     dataFrame.to_excel(writer, sheet_name='page1', float_format='%.6f')
13     dataFrame2.to_excel(writer, sheet_name='page2', float_format='%.6f')

结果：