1、使用worksheet.set_column()设置列宽

遍历每一列并使用worksheet.set_column来设置列宽为该列内容的最大长度，注意这样设置不适合列标题，仅适合列值。

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)
#输出一些SQL Server数据到dataframe
my_sql_query = """ SELECT * FROM dbo.my_table """
my_dataframe = pd.read_sql_query(my_sql_query,con=read_engine)
#设置保存excel的目标目录
xlsFilepath = r'H:\my_project' + "\\" + 'my_file_name.xlsx'
writer = pd.ExcelWriter(xlsFilepath, engine='xlsxwriter')
#写excel文件使用pandas to_excel
my_dataframe.to_excel(writer, startrow = 1, sheet_name='Sheet1', index=False)
workbook = writer.book
worksheet = writer.sheets['Sheet1']
#遍历每一列并设置width ==该列的最大长度。填充长度也增加了2。
for i, col in enumerate(my_dataframe.columns):
    # 求列I的长度
    column_len = my_dataframe[col].astype(str).str.len().max()
    # 如果列标题较大，则设置长度
    # 大于最大列值长度
    column_len = max(column_len, len(col)) + 2
    # 设置列的长度
    worksheet.set_column(i, i, column_len)
writer.save()

或者

# 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()

2、使用StyleFrame自动调整

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