Posts

Showing posts with the label regular-expressions

Featured Post

SQL Interview Success: Unlocking the Top 5 Frequently Asked Queries

Image
 Here are the five top commonly asked SQL queries in the interviews. These you can expect in Data Analyst, or, Data Engineer interviews. Top SQL Queries for Interviews 01. Joins The commonly asked question pertains to providing two tables, determining the number of rows that will return on various join types, and the resultant. Table1 -------- id ---- 1 1 2 3 Table2 -------- id ---- 1 3 1 NULL Output ------- Inner join --------------- 5 rows will return The result will be: =============== 1  1 1   1 1   1 1    1 3    3 02. Substring and Concat Here, we need to write an SQL query to make the upper case of the first letter and the small case of the remaining letter. Table1 ------ ename ===== raJu venKat kRIshna Solution: ========== SELECT CONCAT(UPPER(SUBSTRING(name, 1, 1)), LOWER(SUBSTRING(name, 2))) AS capitalized_name FROM Table1; 03. Case statement SQL Query ========= SELECT Code1, Code2,      CASE         WHEN Code1 = 'A' AND Code2 = 'AA' THEN "A" | "A

How to Search for Single CHAR in Python Using Regular-expression

Image
Here is the logic for searching single CHAR using regular expression(Regex). For instance, we use wildcards to search for anything on our computers. The Regex in Python works similarly. Regular expression People use asterisk * for searching any document. For instance, if you type *.pdf, it returns all the pdfs available in the location (where you are conducting your search). Similar way, in Python, you can search using regular expressions. Import Regex  The first thing you need to do is import 're' if you want to work with regular expressions. import re The Python regular expression library, you can use to improve your skills. Example program: search for single CHAR To match any single character, you can use  [….] . Below, you will find an example to search for: 'l' or 'a' or 'b' import re pattern = r'[lab]' sequence = 'we love python' obj = re.search(pattern,sequence) if obj: print("We found a match here @",obj.group()) else: p

How to write Regular expression Quickly in python and Examples

Image
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 Regular Expressions What is a regular expression How does python support 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 Data mining - to get required data if it is present are not 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. >>>imp