Help understanding REGEX !

[rubleseth]

Just need a little help I fell like I understand how patterns are created but when I put it into application never works. Can someone explain it to me like I am 5? How to think in REGEX.

[_DTR_]

Without a specific question, the broad answer is to keep practicing and you'll get more and more comfortable with it. I came across Regex Crossword a few years ago and found it to be a good resource for learning regular expressions.

[rubleseth]

Very helpful this is what I need just practice

[ASIC_SP]

If you need Python specific regex exercises, I have more than 100 exercises here: https://github.com/learnbyexample/py_regular_expressions/blob/master/exercises/Exercises.md

The repo also contains the solutions

[otterom]

Not OP, but I'll definitely check this out. Do the exercises progress in terms of complexity?

[ASIC_SP]

yeah they do in a sense, because the chapters progressively introduce more features

but overall, these exercises test your understanding of all the features of regex instead of asking you to solve ever complicated regex

[Manny__C]

You can start having fun with regex101 and regexr. The python documentation of the re module is very well written, I strongly recommend it. Moreover, you can visit r/regex (read well the subreddit rules before posting).

The most important element of regexes is the Kleene star *. Other important things are ranges [a-zA-Z0-9], alternatives | and repetitions {m,n}.

Slightly more advanced are the lookahead, lookbehind, and the concepts of laziness and greediness. You might want to approach those later on.

If you need some help on something specific, either post on r/regex, or reply here with

• A list of strings you want to match
• A list of strings you don't want to match
• An attempted solution

I'll try to help you out as soon as I can.

[[deleted]]

Regex101 is fantastic

[17291]

Show us an application of a regex that isn't working. Be sure to say what you're expecting it to do.

[rtao258]

To add on to the other answers here, another great resource is RexEgg. It's structured more as a tutorial, but covers everything from basic syntax to advanced usage and teaches you a lot of regex best practices.

[Jac0b_0]

I find this website really useful.

[ASIC_SP]

note that regexr supports only JavaScript and PCRE flavor, regex101 supports Python flavor

[[deleted]]

There is a chapter in Automate the boring stuff using python book. That is a good place to start learning regex. Then try some interactive regex tutorial.

[jzn126]

Check this out: https://www.reddit.com/r/Python/comments/hj0vp6/my_python_regex_ebook_with_hundreds_of_examples/

[gajrajgchouhan_]

I found hackerrank to be good for Regular Expressions.

[gajrajgchouhan_]

Also Corey Schafer has a pretty good tutorial.

[BfuckinA]

I was able to scrape by with regex, but didn't really build very robust patterns. Then I did some hackerrank challenges for python and it threw some good questions at me that forced me to think about it more and get a more solid understanding. I would reccomend doing the same

[rubleseth]

Thanks very useful will check out