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How to Read a CSV File from Amazon S3 Using Python (With Headers and Rows Displayed)

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  Introduction If you’re working with cloud data, especially on AWS, chances are you’ll encounter data stored in CSV files inside an Amazon S3 bucket . Whether you're building a data pipeline or a quick analysis tool, reading data directly from S3 in Python is a fast, reliable, and scalable way to get started. In this blog post, we’ll walk through: Setting up access to S3 Reading a CSV file using Python and Boto3 Displaying headers and rows Tips to handle larger datasets Let’s jump in! What You’ll Need An AWS account An S3 bucket with a CSV file uploaded AWS credentials (access key and secret key) Python 3.x installed boto3 and pandas libraries installed (you can install them via pip) pip install boto3 pandas Step-by-Step: Read CSV from S3 Let’s say your S3 bucket is named my-data-bucket , and your CSV file is sample-data/employees.csv . ✅ Step 1: Import Required Libraries import boto3 import pandas as pd from io import StringIO boto3 is...

How to write Regular expression Quickly in python and Examples

Regular Expressions purpose is to find matching string in another string. You will get either 'True' or 'False' as a response. I am not sharing here how to play tennis. My intention is if you just follow ideas, you can play tennis today.

Python supports regular expressions. It has a special library to work with these. I have shared best examples for your quick reference.
 

Python Regular Expressions

  1. What is a regular expression
  2. How does python support
  3. Best examples


1. What is regular expression


>>> haystack = 'My phone number is 213-867-5309.' 
>>> '213-867-5309' in haystack
True


This is just a fundamental use of the regular expression. The real use of Regular Expression comes here. That is - to find if the main has any valid phone number.


Regular expressions also called regexes.

2. Why do we need regx

  1. Data mining - to get required data if it is present are not
  2. Data validations - to get an answer if the received string is valid or not.

Python support


Python has its own regular expression library. That is called re. What you need to do is just import it.

>>>import re


When data matches and not matches

  1. If a match found, it returns the String
  2. If there is no match, it will return null


Example for regex


>>> import re
>>> re.search(r'fox', 'The quick brown fox jumped...')
<_sre.SRE_Match object; span=(16, 19), match='fox'>

Notes: The returned string is 'fox'.


Matching string


>>> match = re.search(r'fox', 'The quick brown fox jumped...')
>>> match.group() 'fox'

Notes: The returned string is 'fox'.



Multiple matches

>>> import re >>> re.findall(r'o', 'The quick brown fox jumped...')
['o', 'o']

Notes: It returns multiple strings.

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