Tags » Regex

Valid Parenthesis String

Given a string consists of (, ), and * where * can represent any one of (, ), and empty. Need to determine whether the given input if valid parenthesis. 194 more words


Do you ask yourself these questions? How can I watch the bitcoin exchange rate? What amount of bitcoins have I mined, but not yet transferred to my wallet, and how Bitcoin scripting compiled to Regular expression to check if wallet adress is You really cannot check if an address is valid with a regular expression. 382 more words


Number of Distinct Subsequences

Given a string (s) and a text pattern (t), find the number of distinct subsequences in s that is equal to t.

Recursion (ETL)

This problem can be thought of as regex matching problem, thus can be solved using recursion. 350 more words

Regular Expression

Regular Expression Matching

Given a regex (supports [^ $ . * alphanumerical]), and a string, determine whether the regex can match the string.

Regex are defined recursively. 482 more words

Web Scraping with Python

Install Beautiful Soup from terminal:

pip install beautifulsoup4

I wrote some personalized functions using such module. Note: since it can just work with HTML files, we need to use urllib to open any url and make it readable as done in following code. 359 more words


Find String Between Two Substrings in Python When There is A Space After First Substring

While there are several posts on StackOverflow that are similar to this, none of them involve a situation when the target string is one space after one of the substrings. 297 more words


Decoding Regex

Regex :-  (+[\\.]{0,1})@(+\\.)+{2,3}

Don’t be afraid after seeing¬† this bunch of brackets and alpha-numeric characters. I am quite sure after reading this blogs, you will easily decode above regex pattern and going to write many regex with an ease. 441 more words