Python - Automatically adjust width of an excel file's columns

Question

Newbie - I have a Python script that adjusts the width of different columns of an excel file, according to the values specified:

import openpyxl
from string import ascii_uppercase

newFile = "D:\Excel Files\abc.xlsx"

wb = openpyxl.load_workbook(filename = newFile)        
worksheet = wb.active

for column in ascii_uppercase:
    if (column=='A'):
        worksheet.column_dimensions[column].width = 30
    elif (column=='B'):
        worksheet.column_dimensions[column].width = 40            
    elif (column=='G'):
        worksheet.column_dimensions[column].width = 45            
    else:
        worksheet.column_dimensions[column].width = 15

wb.save(newFile)

Is there any way through which we can adjust the width of every column to its most optimum value, without explicitly specifying it for different columns (means, without using this "if-elif-elif-......-elif-else" structure)? Thanks!

Answer 1

for col in worksheet.columns:
     max_length = 0
     column = col[0].column_letter # Get the column name
     for cell in col:
         try: # Necessary to avoid error on empty cells
             if len(str(cell.value)) > max_length:
                 max_length = len(str(cell.value))
         except:
             pass
     adjusted_width = (max_length + 2) * 1.2
     worksheet.column_dimensions[column].width = adjusted_width

This could probably be made neater but it does the job. You will want to play around with the adjusted_width value according to what is good for the font you are using when viewing it. If you use a monotype you can get it exact but its not a one-to-one correlation so you will still need to adjust it a bit.

If you want to get fancy and exact without monotype you could sort letters by width and assign each width a float value which you then add up. This would require a third loop parsing each character in the cell value and summing up the result for each column and probably a dictionary sorting characters by width, perhaps overkill but cool if you do it.

Edit: Actually there seems to be a better way of measuring visual size of text: link personally I would prefer the matplotlib technique.

Hope I could be of help, my very first stackoverflow answer =)

Answer 2

Updated version as of openpyxl 3.0.0 (using .columns fails with TypeError: expected <class 'str'>:

for column_cells in ws.columns:
    length = max(len(str(cell.value)) for cell in column_cells)
    ws.column_dimensions[column_cells[0].column_letter].width = length

Answer 3

With the latest openpyxl you can use this:

from openpyxl.utils import get_column_letter
for idx, col in enumerate(worksheet.columns, 1):
    worksheet.column_dimensions[get_column_letter(idx)].auto_size = True

Answer 4

I have a problem with merged_cells and autosize not work correctly, if you have the same problem, you can solve adding the next lines inside code of oldsea

for col in worksheet.columns:
    max_length = 0
    column = col[0].column # Get the column name
    for cell in col:
        if cell.coordinate in worksheet.merged_cells: # not check merge_cells
            continue
        try: # Necessary to avoid error on empty cells
            if len(str(cell.value)) > max_length:
                max_length = len(cell.value)
        except:
            pass
    adjusted_width = (max_length + 2) * 1.2
    worksheet.column_dimensions[column].width = adjusted_width

Answer 5

Based on the comment above and add this post openpyxl - adjust column width size. I succeeded, but the answer should be:

from openpyxl.utils import get_column_letter

for col in ws.columns:
    max_length = 0
    column = get_column_letter(col[0].column)  # Get the column name
    # Since Openpyxl 2.6, the column name is  ".column_letter" as .column became the column number (1-based)
    for cell in col:
        try:  # Necessary to avoid error on empty cells
            if len(str(cell.value)) > max_length:
                max_length = len(cell.value)
        except:
            pass
    adjusted_width = (max_length + 2) * 1.2
    ws.column_dimensions[column].width = adjusted_width

i'm using openpyxl = "^3.0.5"

Answer 6

def auto_format_cell_width(ws):
    for letter in range(1,ws.max_column):
        maximum_value = 0
        for cell in ws[get_column_letter(letter)]:
            val_to_check = len(str(cell.value))
            if val_to_check > maximum_value:
               maximum_value = val_to_check
        ws.column_dimensions[get_column_letter(letter)].width = maximum_value + 1