5 Best Ways to Convert a Python List to an Excel Column

πŸ’‘ Problem Formulation:

Transferring data seamlessly between different formats is a common necessity in programming. In this article, we address the problem of converting a Python list into an Excel column. The objective is to take a Python list, such as ['Apple', 'Banana', 'Cherry'], and export it to an Excel file, with each item occupying a separate row in the same column.

Method 1: Using pandas DataFrame

Pandas is a powerful data manipulation library in Python. To export a list to an Excel column, you can first convert the list into a pandas DataFrame and then use the to_excel() method to save the DataFrame to an Excel file. This approach is straightforward and efficient, especially for large datasets or when dealing with multiple lists.

Here’s an example:

import pandas as pd

fruits = ['Apple', 'Banana', 'Cherry']
df = pd.DataFrame(fruits, columns=['Fruit'])

df.to_excel('fruits.xlsx', index=False)

Output:

An Excel file named 'fruits.xlsx' with the fruits list in the first column.

This code snippet creates a pandas DataFrame using the list of fruits and designates a single column named ‘Fruit’. It then exports the DataFrame to an Excel file without the index to ensure that only the data in the column is saved.

Method 2: Using openpyxl

The openpyxl library is designed to read/write Excel 2010 xlsx/xlsm/xltx/xltm files. You can create a workbook, select the active sheet, populate the rows with the list elements, and save to an Excel file. It offers fine-grained control over the Excel file, enabling the customization of many aspects such as styles, filters, and formulas.

Here’s an example:

from openpyxl import Workbook

wb = Workbook()
ws = wb.active

fruits = ['Apple', 'Banana', 'Cherry']

for row, fruit in enumerate(fruits, start=1):
    ws.cell(row=row, column=1, value=fruit)

wb.save('fruits.xlsx')

Output:

An Excel file named 'fruits.xlsx' with each fruit in a new row in the first column.

This snippet creates a new Excel workbook, selects the active sheet, and then iterates over the list of fruits. Each fruit is written to a new row in the first column of the worksheet. The workbook is then saved as ‘fruits.xlsx’.

Method 3: Using xlsxwriter

xlsxwriter is a Python module that you can use to write text, numbers, formulas, and hyperlinks to multiple worksheets in an Excel 2007+ XLSX file. This method is useful when you need to format the Excel file in very specific ways because it provides control over the Excel format settings.

Here’s an example:

import xlsxwriter

workbook = xlsxwriter.Workbook('fruits.xlsx')
worksheet = workbook.add_worksheet()

fruits = ['Apple', 'Banana', 'Cherry']

for row_num, fruit in enumerate(fruits):
    worksheet.write(row_num, 0, fruit)

workbook.close()

Output:

An Excel file named 'fruits.xlsx' containing a list of fruits, each in a separate row in the first column.

This code utilizes xlsxwriter to create a new Excel file. It then iteratively writes each fruit from our list into the first column of a new worksheet, with each entry going into a subsequent row.

Method 4: Using xlwt

xlwt is an older library for writing data and formatting information to older Excel files (i.e., .xls). Using xlwt is a good choice if you need to work with Excel files older than 2007. However, bear in mind that it cannot write to .xlsx files like the previously mentioned libraries.

Here’s an example:

import xlwt

book = xlwt.Workbook()
sheet = book.add_sheet('Sheet 1')

fruits = ['Apple', 'Banana', 'Cherry']

for index, fruit in enumerate(fruits):
    sheet.write(index, 0, fruit)

book.save('fruits.xls')

Output:

An Excel file named 'fruits.xls' with the list of fruits, where each is in a new row of the first column.

In this snippet, xlwt is used to write each item from the list to a new row in a .xls Excel file. Since xlwt works with the older Excel format, this code is specifically creating ‘fruits.xls’.

Bonus One-Liner Method 5: Using csv.writer

If you only need to create a simple Excel-readable CSV file without formatting, you can use Python’s built-in csv module. This is the most straightforward approach if your data does not require the advanced features of an actual Excel file.

Here’s an example:

import csv

fruits = ['Apple', 'Banana', 'Cherry']

with open('fruits.csv', 'w', newline='') as file:
    writer = csv.writer(file)
    for fruit in fruits:
        writer.writerow([fruit])

Output:

A CSV file named 'fruits.csv' with each fruit listed in the first column.

This code creates a CSV file where each list element is written to a new line, effectively a new row, in a singular column format. CSV files can be read by Excel, making this a quick and simple option for list to column conversion.

Summary/Discussion

  • Method 1: Pandas DataFrame. Strengths: Very powerful for handling large datasets and complicated data manipulations. Weaknesses: Requires the installation of the pandas library and potentially more memory for large data frames.
  • Method 2: Openpyxl. Strengths: Allows for detailed customization of the Excel file, good for advanced Excel operations. Weaknesses: Slower than some other methods and requires understanding of the openpyxl library.
  • Method 3: Xlsxwriter. Strengths: Offers extensive formatting options and it is suitable for creating complex Excel files programmatically. Weaknesses: Does not read Excel files and slightly more verbose syntax.
  • Method 4: Xlwt. Strengths: Good for maintaining compatibility with older Excel file formats (.xls). Weaknesses: Limited to old formats and lacks support for newer Excel features.
  • Method 5: CSV.writer. Strengths: Built into Python, so no additional libraries are required. Creates lightweight files quickly. Weaknesses: Limited formatting and functionality compared to actual Excel files.