Merge two csv files using Python

Hey there! If you’ve ever worked with data, chances are you’ve come across CSV files. They’re super handy for storing tabular data, but sometimes, you end up with multiple CSV files that you need to combine into one. Don’t worry! it’s easier than it sounds! In this guide, I’ll walk you through how to Merge two CSV files using Python. But first, let’s quickly go over what a CSV file actually is.

What is a CSV File?

So, what exactly is a CSV file? CSV stands for Comma-Separated Values. It’s basically a simple text file where each line represents a row of data, and each value in the row is separated by comma(‘ , ‘)

ID,Name,Age
1,John Doe,28
2,Jane Smith,34
3,Bob Johnson,45

In the example above, the first line is the header (column names), and the following lines are the data rows. CSV files are super popular because they’re lightweight and can be easily opened in spreadsheet applications like Excel.

Step-by-Step Guide to Merge Two CSV Files

Now that we know what a CSV file is, let’s dive into the fun part: merging two of them using Python!

Step 1: Install the Required Libraries

To start, make sure you have Python installed on your computer. We’re going to use the pandas library, which is awesome for data manipulation. If you haven’t installed it yet, just run this command in your terminal or command prompt:

pip install pandas
Step 2: Prepare Your CSV Files

Before you start coding, make sure your two CSV files are ready to go. Let’s assume they’re named file1.csv and file2.csv. For best results, these files should have at least one column in common, like an ID number or a name.

Step 3: Load the CSV Files

Next, we’ll use the pandas library to read the CSV files into Python. Here’s how you do it:

import pandas as pd

df1 = pd.read_csv('file1.csv')
df2 = pd.read_csv('file2.csv')

File1.csv Image Alt Text: "Table showing data from File1.csv with columns ID, Name, and Age, including John Doe, 28, and Jane Smith, 34." File2.csv Image Alt Text: "Table showing data from File2.csv with columns ID and Email, including john.doe@example.com and jane.smith@example.com."

This code will load your CSV files into pandas DataFrames, which are like supercharged spreadsheets!

Step 4: Merge the CSV Files

Now comes the magic part: merging the files! If both CSV files have a common column (like an ‘ID’), you can use the merge() function:

merged_df = pd.merge(df1, df2, on='ID')

If you just want to stack the two files on top of each other, you can use the concat() function (that is there is no columns in common):

concatenated_df = pd.concat([df1, df2], axis=0)
Step 5: Save the Merged File

Once you’ve merged the files, it’s time to save the result to a new CSV file. Here’s how:

merged_df.to_csv('merged_file.csv', index=False)

Table showing merged data from File1.csv and File2.csv with columns ID, Name, Age, and Email. The table includes John Doe, Age 28, and his email john.doe@example.com, as well as Jane Smith, Age 34, and her email jane.smith@example.com.

And that’s it! You now have a shiny new CSV file that combines the data from both of your original files.

Conclusion

Merging CSV files in Python is actually pretty simple once you get the hang of it. With the help of the pandas library, you can quickly combine files and make your data analysis life a lot easier. Just remember to check your data after merging to make sure everything looks right!

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