A Comprehensive Guide to ETL Data Processing on Google Cloud Storage with Pandas.
Published: 2023-10-24 14:27:50

[](Image by <a href="https://www.freepik.com/free-photo/rpa-concept-with-blurry-hand-touching-screen_23992698.htm#query=processing&position=3&from_view=search&track=sph">Freepik</a>)

In today's data-driven world, efficiently processing and transforming data is a critical task for businesses and organizations. This article will guide you through the process of extracting, transforming, and loading (ETL) data using a combination of powerful tools and libraries: Google Cloud Storage,and Pandas. We'll demonstrate this ETL process by fetching a CSV file from Google Cloud Storage, performing data transformations, and uploading the processed data back to the same cloud storage location as a parquet file.


### Setting Up Your Environment

- Install python.
-create a virtual environment.
- Have a Google Cloud account and bucket with CSV data file.
-install pandas library
- Download the key from Google Cloud service account.

**create python virtual environment**

![create virtual environment ](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/35r1iu6fkdgpns13wydd.png)

**activate the python virtual environment**


![activate virtual environment](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/v5zm29r6t0wlr9w8e5aw.png)

- Now that your virtual environment is active, you can install Python packages using pip

![Install the libraries](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/rjbuu15q2khz0ubeuewj.png)
**Connecting to Google Cloud Storage**
 - Importing the required libraries.

![Import the libraries](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/un9e99d5zne6qs1shhec.png)

**Authenticating with Google Cloud using a service account key.**
  - Accessing your Google Cloud Storage bucket.

![accessing cloud storage](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/kitwjdb9p1spd6e5cdau.png)

- The files in a cloud storage

![files in google cloud storage](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/fgzdwxsitlbboctw2nbz.png)

- Retrieving a CSV file from the google storage bucket.

![reading file](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/noigcg1zxp4dng4o4mnq.png)

- Downloading and reading the CSV data using Pandas dataframe

![reading file and download](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/uwkepmskswxvlz3nnq99.png)

### Data Transformation with Pandas and Polars
   - Preparing your data for analysis.
   - Grouping data by 'cust_id' and 'transaction_category'

![Data transformation](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ms9p5if0o0ckjfivp8bk.png)

### Uploading Processed Data Back to Google Cloud Storage
   - Creating a new bucket or selecting an existing one bucket to use.


![uploading to bucket](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/monm02eop9p4eam8f689.png)
   - Specifying a blob (object) name for the processed data.
   - Uploading the transformed data back to Google Cloud Storage.

![processing data](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/jwgyc5qrkxhzd7qt7svq.png)

## Conclusion
In the modern data landscape, mastering the ETL process is crucial for organizations to harness the full potential of their data. This comprehensive guide has equipped you with the knowledge and skills needed to seamlessly extract data from Google Cloud Storage, perform transformations using Pandas, and efficiently load the processed data back into the cloud in parquet format. With the power of these tools and libraries at your disposal, you are well-prepared to tackle data processing challenges in your projects and make informed decisions based on your data