Is there a way to auto-adjust Excel column widths with pandas.ExcelWriter?

Question

I am being asked to generate some Excel reports. I am currently using pandas quite heavily for my data, so naturally I would like to use the pandas.ExcelWriter method to generate these reports. However the fixed column widths are a problem.

The code I have so far is simple enough. Say I have a dataframe called df:

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

I was looking over the pandas docs, and I don't really see any options to set column widths. Is there a trick to make it such that the columns auto-adjust to the data? Or is there something I can do after the fact to the xlsx file to adjust the column widths?

(I am using the OpenPyXL library, and generating .xlsx files - if that makes any difference.)

Answer 1

Inspired by user6178746's answer, I have the following:

# 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()

Answer 2

Dynamically adjust all the column lengths

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)

writer.save()

---

Manually adjust a column using Column Name

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

---

Manually adjust a column using Column Index

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

---

In case any of the above is failing with

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

make sure to install xlsxwriter:

pip install xlsxwriter

and use it as the engine:

writer = pd.ExcelWriter('/path/to/output/file.xlsx', engine='xlsxwriter') 

---

For a more comprehensive explanation you can read the article How to Auto-Adjust the Width of Excel Columns with Pandas ExcelWriter on TDS.

Answer 3

There is a nice package that I started to use recently called StyleFrame.

it gets DataFrame and lets you to style it very easily...

by default the columns width is auto-adjusting.

for example:

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()

you can also change the columns width:

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

UPDATE 1

In version 1.4 best_fit argument was added to StyleFrame.to_excel. See the documentation.

UPDATE 2

Here's a sample of code that works for StyleFrame 3.x.x

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()

Answer 4

I'm posting this because I just ran into the same issue and found that the official documentation for Xlsxwriter and pandas still have this functionality listed as unsupported. I hacked together a solution that solved the issue i was having. I basically just iterate through each column and use worksheet.set_column to set the column width == the max length of the contents of that column.

One important note, however. This solution does not fit the column headers, simply the column values. That should be an easy change though if you need to fit the headers instead. Hope this helps someone :)

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()

Answer 5

There is probably no automatic way to do it right now, but as you use openpyxl, the following line (adapted from another answer by user Bufke on how to do in manually) allows you to specify a sane value (in character widths):

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

Answer 6

By using pandas and xlsxwriter you can do your task, below code will perfectly work in Python 3.x. For more details on working with XlsxWriter with pandas this link might be useful 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()

Answer 7

I found that it was more useful to adjust the column with based on the column header rather than column content.

Using df.columns.values.tolist() I generate a list of the column headers and use the lengths of these headers to determine the width of the columns.

See full code below:

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

Answer 8

At work, I am always writing the dataframes to excel files. So instead of writing the same code over and over, I have created a modulus. Now I just import it and use it to write and formate the excel files. There is one downside though, it takes a long time if the dataframe is extra large. So here is the code:

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()
    return output_dir + output_name

Answer 9

Combining the other answers and comments and also supporting multi-indices:

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()

Answer 10

Yes, there is there is something you can do subsequently to the xlsx file to auto-adjust the column widths. Use xlwings to autofit columns. It's a pretty simple solution, see the 6 last lines of the example code. The advantage of this procedure is that you don't have to worry about font size, font type or anything else. Requirement: Excel installation.

import pandas as pd
import xlwings as xw

path = r"test.xlsx"

# Export your dataframe in question.
df = pd._testing.makeDataFrame()
df.to_excel(path)

# Autofit all columns with xlwings.
with xw.App(visible=False) as app:
    wb = xw.Book(path)

    for ws in wb.sheets:
        ws.autofit(axis="columns")

    wb.save(path)
    wb.close()

Answer 11

you can solve the problem by calling the following function, where df is the dataframe you want to get the sizes and the sheetname is the sheet in excel where you want the modifications to take place

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)

Answer 12

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

Answer 13

Please try to use worksheet.autofit() I have reached this method with pip install XlsxWriter==3.0.9

P.S. I'm newbie to writing answers, I apologize for the dryness of the answer.

Answer 14

Easiest solution is to specify width of column in set_column method.

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

Answer 15

This function works for me, also fixes the index width

def write_to_excel(writer, X, sheet_name, sep_only=False):
    #writer=writer object
    #X=dataframe
    #sheet_name=name of sheet
    #sep_only=True:write only as separate excel file, False: write as sheet to the writer object
    if sheet_name=="": 
        print("specify sheet_name!")
    else:
        X.to_excel(f"{output_folder}{prefix_excel_save}_{sheet_name}.xlsx")
        if not sep_only: 
            X.to_excel(writer, sheet_name=sheet_name)
            
            #fix column widths
            worksheet = writer.sheets[sheet_name]  # pull worksheet object
            for idx, col in enumerate(X.columns):  # loop through all columns
                series = X[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+1, idx+1, max_len)  # set column width (=1 because index = 1)
                
            #fix index width
            max_len=pd.Series(X.index.values).astype(str).map(len).max()+1
            worksheet.set_column(0, 0, max_len)
            
        if sep_only: 
            print(f'{sheet_name} is written as seperate file')
        else:
            print(f'{sheet_name} is written as seperate file')
            print(f'{sheet_name} is written as sheet')
    return writer

call example:

writer = write_to_excel(writer, dataframe, "Statistical_Analysis")

Answer 16

A lot of valid solutions on here. I think the easiest and cleanest way to achieve is using Microsoft's pywin32 package which closely mirrors Excel VBA. The Range.AutoFit method takes care of this issue. Example below:

import win32com.client as win32

xlApp = win32.Dispatch('Excel.Application')
wb = xlApp.Workbooks.Open(***file path to excel file goes here***)

ws = wb.Worksheets[***name of worksheet trying adjust column width***]
ws.Columns.AutoFit()

Note: Worksheet.Columns property represents a Range object. Autofit is a method that belongs to the Range object.

Answer 17

I may be a bit late to the party but this code works when using 'openpyxl' as your engine, sometimes pip install xlsxwriter wont solve the issue. This code below works like a charm. Edit any part as you wish.

def text_length(text):
    """
    Get the effective text length in characters, taking into account newlines
    """
    if not text:
        return 0
    lines = text.split("\n")
    return max(len(line) for line in lines)

def _to_str_for_length(v, decimals=3):
    """
    Like str() but rounds decimals to predefined length
    """
    if isinstance(v, float):
        # Round to [decimal] places
        return str(Decimal(v).quantize(Decimal('1.' + '0' * decimals)).normalize())
    else:
        return str(v)


def auto_adjust_xlsx_column_width(df, writer, sheet_name, margin=3, length_factor=1.0, decimals=3, index=False):

    sheet = writer.sheets[sheet_name]
    _to_str = functools.partial(_to_str_for_length, decimals=decimals)
    # Compute & set column width for each column
    for column_name in df.columns:
        # Convert the value of the columns to string and select the 
        column_length =  max(df[column_name].apply(_to_str).map(text_length).max(), text_length(column_name)) + 5
        # Get index of column in XLSX
        # Column index is +1 if we also export the index column
        col_idx = df.columns.get_loc(column_name)
        if index:
            col_idx += 1
        # Set width of column to (column_length + margin)
        sheet.column_dimensions[openpyxl.utils.cell.get_column_letter(col_idx + 1)].width = column_length * length_factor + margin
    # Compute column width of index column (if enabled)
    if index: # If the index column is being exported
        index_length =  max(df.index.map(_to_str).map(text_length).max(), text_length(df.index.name))
        sheet.column_dimensions["A"].width = index_length * length_factor + margin

Answer 18

An openpyxl version based on @alichaudry's code.
The code 1) loads an excel file, 2) adjusts column widths and 3) saves it.

def auto_adjust_column_widths(excel_file : "Excel File Path", extra_space = 1) -> None:
    """
    Adjusts column widths of the excel file and replaces it with the adjusted one.
    Adjusting columns is based on the lengths of columns values (including column names).
    Parameters
    ----------
    excel_file :
        excel_file to adjust column widths.
    
    extra_space : 
        extra column width in addition to the value-based-widths
    """

    from openpyxl import load_workbook
    from openpyxl.utils import get_column_letter


    wb = load_workbook(excel_file)

    
    for ws in wb:
        df = pd.DataFrame(ws.values,)

        
        for i,r in (df.astype(str).applymap(len).max(axis=0) + extra_space).iteritems():
            ws.column_dimensions[get_column_letter(i+1)].width = r

    
    wb.save(excel_file)

Answer 19

attention, in previuos answers a lot of outdated methods and hard crutches.

FutureWarning: save is not part of the public API, usage can give unexpected results and will be removed in a future version
  writer.save()

i found an easy solution for this old, but important problem:

from UliPlot.XLSX import auto_adjust_xlsx_column_width

with pd.ExcelWriter("example.xlsx") as writer:
    df.to_excel(writer, sheet_name="MySheet")
    auto_adjust_xlsx_column_width(df, writer, sheet_name="MySheet", margin=1)

THAT IS ALL YOU NEED

the decision is not mine, so I have to post a link to the author, you can thank him

Answer 20

Since you are using openpyxl engine, you can try this below solution. The columns get adjusted automatically

for column_cells in sheet.columns:
    new_column_length = max(len(str(cell.value)) for cell in column_cells)
    new_column_letter = (get_column_letter(column_cells[0].column))
    if new_column_length > 0:
        sheet.column_dimensions[new_column_letter].width = new_column_length*1.23