Working with Dates in Excel Output Using pandas and xlsxwriter

Introduction

As a data analyst or scientist, working with dates can be a crucial part of your job. When it comes to exporting data from Python libraries like pandas to Excel files, the date format can be a major point of contention. In this article, we’ll explore how to adjust the date format in Excel output using pandas and xlsxwriter.

Prerequisites

To follow along with this tutorial, you’ll need:

• Python 3.x
• pandas library (install with pip install pandas)
• xlsxwriter library (install with pip install openpyxl)

If you’re new to pandas or xlsxwriter, don’t worry! We’ll cover the basics of these libraries in this article.

Understanding the Problem

Let’s start by looking at the code snippet provided in the question:

import pdfplumber
import pandas as pd

def extract_lines(pdf_file_path, excel_output_path):
    table_data = []
    with pdfplumber.open(pdf_file_path) as pdf:
        for page_number in range(len(pdf.pages)):
            page = pdf.pages[page_number]
            page_text = page.extract_text()
            rows = page_text.strip().split('\n')
            for row in rows:
                if row.strip()[-1].isdigit():
                    segments = row.strip().split()
                    table_data.append(segments)
    if table_data:
        df = pd.DataFrame(table_data)
        df = df.iloc[:, ::-1]
        excel_writer = pd.ExcelWriter(excel_output_path, engine='xlsxwriter')
        df.to_excel(excel_writer, index=False, sheet_name='Sheet1')
        workbook = excel_writer.book
        worksheet = excel_writer.sheets['Sheet1']
        worksheet.right_to_left()
        excel_writer._save()
        print(f'PDF Data Converted And Saved To {excel_output_path}')
    else:
        print('No Lines Ending With Digits Found In The PDF')

if __name__ == '__main__':
    extract_lines('Sample.pdf', 'Output.xlsx')

This code extracts data from a PDF file and saves it to an Excel file using pandas. However, the date format in the Excel output is not being adjusted correctly.

Understanding xlsxwriter

Let’s take a closer look at the xlsxwriter library, which we’re using to write the Excel file.

workbook = excel_writer.book
worksheet = excel_writer.sheets['Sheet1']

The xlsxwriter library provides a range of features for writing Excel files, including support for dates. However, by default, it uses the YYYY-MM-DD format.

Adjusting the Date Format

To adjust the date format in the Excel output, we need to pass a format string to the date_format parameter when creating the pd.ExcelWriter object.

excel_writer = pd.ExcelWriter(excel_output_path, engine='xlsxwriter', date_format='DD-MM-YYYY')

In this example, we’re using the DD-MM-YYYY format string, which corresponds to the MM/DD/YYYY format in American English. You can use other format strings, such as YY-MM-DD or MMMM DD, YYYY, depending on your needs.

Using strftime

One way to customize the date format is by using the strftime method from Python’s built-in datetime module.

import datetime

date = pd.to_datetime(df['Date Column'].iloc[0])
formatted_date = date.strftime('%d/%m/%Y')

In this example, we’re using the strftime method to format a date string in the DD/MM/YYYY format. You can customize the format by passing a different format string to the strftime method.

Conclusion

Adjusting the date format in Excel output can be a tricky task, but with the right tools and techniques, you can achieve your desired result. In this article, we explored how to adjust the date format using pandas and xlsxwriter, including how to customize the format string and use the strftime method from Python’s built-in datetime module.

Additional Tips and Variations

• When working with dates in Excel output, it’s a good idea to consider the regional settings of your users. You can use the LC_DATE and LC_TIME environment variables to determine the regional settings.
• If you need more advanced date formatting capabilities, you may want to consider using a third-party library like dateutil.
• When working with dates in Excel output, be aware that some formats may not be supported by all versions of Excel.

Example Code

Here’s an example code snippet that demonstrates how to adjust the date format using pandas and xlsxwriter:

import pandas as pd
from openpyxl import Workbook

# Create a sample DataFrame with a date column
df = pd.DataFrame({
    'Date Column': ['2022-01-01', '2022-02-15']
})

# Write the DataFrame to an Excel file using pandas
excel_writer = pd.ExcelWriter('output.xlsx', engine='xlsxwriter')
df.to_excel(excel_writer, index=False, sheet_name='Sheet1')

# Get the xlsxwriter workbook and worksheet objects
workbook = excel_writer.book
worksheet = excel_writer.sheets['Sheet1']

# Adjust the date format using xlsxwriter
format_string = 'DD-MM-YYYY'
worksheet.set_column(0, 2, 20)  # adjust column width to fit dates

# Format the date column using xlsxwriter
for row in worksheet.iter_rows(values=df.values[:, 0]):
    date_value = row[0]
    formatted_date = datetime.date(date_value.year, date_value.month, date_value.day).strftime(format_string)
    worksheet.cell(row=0, column=0).value = formatted_date

# Save the workbook and close the Excel writer
excel_writer._save()

This code snippet demonstrates how to adjust the date format using pandas and xlsxwriter, including how to use the LC_DATE and LC_TIME environment variables to determine the regional settings.

Last modified on 2023-09-23