有没有一种方法可以使用pandas.ExcelWriter自动调整Excel列的宽度？

我被要求生成一些Excel报告。我目前正在大量使用pandas作为数据，所以自然地我想使用pandas.ExcelWriter方法生成这些报告。但是，固定的列宽是一个问题。

到目前为止，我的代码很简单。假设我有一个名为“ df”的数据框：

writer = pd.ExcelWriter(excel_file_path, engine='openpyxl')
df.to_excel(writer, sheet_name="Summary")

我正在查看pandas代码，但实际上没有看到任何设置列宽的选项。宇宙中是否有技巧可以使列自动调整为数据？还是在事实之后我可以对xlsx文件做一些事情来调整列宽？

（我正在使用OpenPyXL库，并生成.xlsx文件-如果有区别的话。）

谢谢。

受user6178746的回答启发，我有以下内容：

# Given a dict of dataframes, for example:
# dfs = {'gadgets': df_gadgets, 'widgets': df_widgets}

writer = pd.ExcelWriter(filename, engine='xlsxwriter')
for sheetname, df in dfs.items():  # loop through `dict` of dataframes
    df.to_excel(writer, sheet_name=sheetname)  # send df to writer
    worksheet = writer.sheets[sheetname]  # pull worksheet object
    for idx, col in enumerate(df):  # loop through all columns
        series = df[col]
        max_len = max((
            series.astype(str).map(len).max(),  # len of largest item
            len(str(series.name))  # len of column name/header
            )) + 1  # adding a little extra space
        worksheet.set_column(idx, idx, max_len)  # set column width
writer.save()

我发布此消息是因为我遇到了同样的问题，发现Xlsxwriter和pandas的官方文档仍然将此功能列为不受支持。我找到了解决我遇到的问题的解决方案。我基本上只是遍历每列，并使用worksheet.set_column设置列宽==该列内容的最大长度。

但是，重要的一点。此解决方案不适合列标题，仅适合列值。这应该是一个容易的更改，但是，如果您需要改头，则可以。希望这可以帮助某人:)

import pandas as pd
import sqlalchemy as sa
import urllib


read_server = 'serverName'
read_database = 'databaseName'

read_params = urllib.quote_plus("DRIVER={SQL Server};SERVER="+read_server+";DATABASE="+read_database+";TRUSTED_CONNECTION=Yes")
read_engine = sa.create_engine("mssql+pyodbc:///?odbc_connect=%s" % read_params)

#Output some SQL Server data into a dataframe
my_sql_query = """ SELECT * FROM dbo.my_table """
my_dataframe = pd.read_sql_query(my_sql_query,con=read_engine)

#Set destination directory to save excel.
xlsFilepath = r'H:\my_project' + "\\" + 'my_file_name.xlsx'
writer = pd.ExcelWriter(xlsFilepath, engine='xlsxwriter')

#Write excel to file using pandas to_excel
my_dataframe.to_excel(writer, startrow = 1, sheet_name='Sheet1', index=False)

#Indicate workbook and worksheet for formatting
workbook = writer.book
worksheet = writer.sheets['Sheet1']

#Iterate through each column and set the width == the max length in that column. A padding length of 2 is also added.
for i, col in enumerate(my_dataframe.columns):
    # find length of column i
    column_len = my_dataframe[col].astype(str).str.len().max()
    # Setting the length if the column header is larger
    # than the max column value length
    column_len = max(column_len, len(col)) + 2
    # set the column length
    worksheet.set_column(i, i, column_len)
writer.save()

现在可能尚无自动方法，但是当您使用openpyxl时，以下几行（由Bufke用户改写了有关手动操作的另一答案）允许您指定合理的值（以字符宽度表示）：

writer.sheets['Summary'].column_dimensions['A'].width = 15

我最近开始使用一个不错的程序包，称为StyleFrame。

它获得了DataFrame并允许您非常轻松地对其进行样式设置...

默认情况下，列宽是自动调整的。

例如：

from StyleFrame import StyleFrame
import pandas as pd

df = pd.DataFrame({'aaaaaaaaaaa': [1, 2, 3], 
                   'bbbbbbbbb': [1, 1, 1],
                   'ccccccccccc': [2, 3, 4]})
excel_writer = StyleFrame.ExcelWriter('example.xlsx')
sf = StyleFrame(df)
sf.to_excel(excel_writer=excel_writer, row_to_add_filters=0,
            columns_and_rows_to_freeze='B2')
excel_writer.save()

您还可以更改列宽：

sf.set_column_width(columns=['aaaaaaaaaaa', 'bbbbbbbbb'],
                    width=35.3)

更新

在1.4版中，best_fit参数已添加到中StyleFrame.to_excel。请参阅文档。

通过使用pandas和xlsxwriter，您可以完成任务，下面的代码将在Python 3.x中完美地工作。有关使用XlsxWriter和熊猫的更多详细信息，此链接可能会有用：https: //xlsxwriter.readthedocs.io/working_with_pandas.html

import pandas as pd
writer = pd.ExcelWriter(excel_file_path, engine='xlsxwriter')
df.to_excel(writer, sheet_name="Summary")
workbook = writer.book
worksheet = writer.sheets["Summary"]
#set the column width as per your requirement
worksheet.set_column('A:A', 25)
writer.save()

我发现基于列标题而不是列内容来调整列更有用。

使用 df.columns.values.tolist() I生成列标题的列表，并使用这些标题的长度来确定列的宽度。

请参阅下面的完整代码：

import pandas as pd
import xlsxwriter

writer = pd.ExcelWriter(filename, engine='xlsxwriter')
df.to_excel(writer, index=False, sheet_name=sheetname)

workbook = writer.book # Access the workbook
worksheet= writer.sheets[sheetname] # Access the Worksheet

header_list = df.columns.values.tolist() # Generate list of headers
for i in range(0, len(header_list)):
    worksheet.set_column(i, i, len(header_list[i])) # Set column widths based on len(header)

writer.save() # Save the excel file

在工作中，我总是将数据帧写入excel文件。因此，我没有反复编写相同的代码，而是创建了一个模数。现在，我只是将其导入并使用它来编写和设置excel文件。但是有一个缺点，如果数据帧过大，则需要花费很长时间。所以这是代码：

def result_to_excel(output_name, dataframes_list, sheet_names_list, output_dir):
    out_path = os.path.join(output_dir, output_name)
    writerReport = pd.ExcelWriter(out_path, engine='xlsxwriter',
                    datetime_format='yyyymmdd', date_format='yyyymmdd')
    workbook = writerReport.book
    # loop through the list of dataframes to save every dataframe into a new sheet in the excel file
    for i, dataframe in enumerate(dataframes_list):
        sheet_name = sheet_names_list[i]  # choose the sheet name from sheet_names_list
        dataframe.to_excel(writerReport, sheet_name=sheet_name, index=False, startrow=0)
        # Add a header format.
        format = workbook.add_format({
            'bold': True,
            'border': 1,
            'fg_color': '#0000FF',
            'font_color': 'white'})
        # Write the column headers with the defined format.
        worksheet = writerReport.sheets[sheet_name]
        for col_num, col_name in enumerate(dataframe.columns.values):
            worksheet.write(0, col_num, col_name, format)
        worksheet.autofilter(0, 0, 0, len(dataframe.columns) - 1)
        worksheet.freeze_panes(1, 0)
        # loop through the columns in the dataframe to get the width of the column
        for j, col in enumerate(dataframe.columns):
            max_width = max([len(str(s)) for s in dataframe[col].values] + [len(col) + 2])
            # define a max width to not get to wide column
            if max_width > 50:
                max_width = 50
            worksheet.set_column(j, j, max_width)
    writerReport.save()
    writerReport.close()
    return output_dir + output_name

动态调整所有列长

writer = pd.ExcelWriter('/path/to/output/file.xlsx') 
df.to_excel(writer, sheet_name='sheetName', index=False, na_rep='NaN')

for column in df:
    column_length = max(df[column].astype(str).map(len).max(), len(column))
    col_idx = df.columns.get_loc(column)
    writer.sheets['sheetName'].set_column(col_idx, col_idx, column_length)

使用列名手动调整列

col_idx = df.columns.get_loc('columnName')
writer.sheets['sheetName'].set_column(col_idx, col_idx, 15)

使用列索引手动调整列

writer.sheets['sheetName'].set_column(col_idx, col_idx, 15)

如果以上任何一个失败

AttributeError: 'Worksheet' object has no attribute 'set_column'

确保安装xlsxwriter：

pip install xlsxwriter

结合其他答案和评论，还支持多索引：

def autosize_excel_columns(worksheet, df):
  autosize_excel_columns_df(worksheet, df.index.to_frame())
  autosize_excel_columns_df(worksheet, df, offset=df.index.nlevels)

def autosize_excel_columns_df(worksheet, df, offset=0):
  for idx, col in enumerate(df):
    series = df[col]
    max_len = max((
      series.astype(str).map(len).max(),
      len(str(series.name))
    )) + 1
    worksheet.set_column(idx+offset, idx+offset, max_len)

sheetname=...
df.to_excel(writer, sheet_name=sheetname, freeze_panes=(df.columns.nlevels, df.index.nlevels))
worksheet = writer.sheets[sheetname]
autosize_excel_columns(worksheet, df)
writer.save()

import re
import openpyxl
..
for col in _ws.columns:
    max_lenght = 0
    print(col[0])
    col_name = re.findall('\w\d', str(col[0]))
    col_name = col_name[0]
    col_name = re.findall('\w', str(col_name))[0]
    print(col_name)
    for cell in col:
        try:
            if len(str(cell.value)) > max_lenght:
                max_lenght = len(cell.value)
        except:
            pass
    adjusted_width = (max_lenght+2)
    _ws.column_dimensions[col_name].width = adjusted_width

最简单的解决方案是在set_column方法中指定列宽。

    for worksheet in writer.sheets.values():
        worksheet.set_column(0,last_column_value, required_width_constant)

def auto_width_columns(df, sheetname):
    workbook = writer.book  
    worksheet= writer.sheets[sheetname] 

    for i, col in enumerate(df.columns):
        column_len = max(df[col].astype(str).str.len().max(), len(col) + 2)
        worksheet.set_column(i, i, column_len)