Need a little extra help with those Regular Expression(regex) functions? Then look no further! Here, I have put together the best top 10 regex cheat sheets for you to download, print and pin to the bathroom wall!!

1. Python Regex Cheat Sheet Examples Free
2. Regex Cheat Sheet Php
3. Regular Expression Cheat Sheet Python
4. Regex Cheat Sheet
5. Perl Regex Cheat Sheet Pdf
6. Python Regex Cheat Sheet Examples Download

Regular expressions, also called regex, is a syntax or rather a language to search, extract and manipulate specific string patterns from a larger text. In python, it is implemented in the re module. You will first get introduced to the 5 main features of the re module and then see how to create common regex in python.

• Python regular expression cheat sheet. Python regular expression cheat sheet example: python regex Matching pattern: Result: python regex replace: There are different way to regex replace; sach Pagar.
• Regular expressions are handled as strings by Python. However, with compile, you can computer a regular expression pattern into a regular expression object. When you need to use an expression several times in a single program, using compile to save the resulting regular expression object for reuse is more efficient than saving it as a string.
• 🔥Python Certification Training: Edureka 'Python RegEx' tutorial (Python Tutorial Blog: h.

This cheat sheets will be a great reference when you need to put them in your scripts when you are web scraping and trying to find information or when you need help to authenticate users and passwords!

All the regex cheat sheets in this article are 100% free. All links open a new tab (feel free to open all the links without losing this page!)

Cheat Sheet 1: Rexegg.com

This first sheet is from Rexegg.com. The entire list is one that is commonly used Regex expressions in Python and other languages. This list includes Characters, Quantifiers and more. It will even tell you what language this expression can be used in! This makes it a lot easier when you go to write a regex in your language preference. This website really does emphasize looking at the tables for the expressions by keeping the tables bright on a black background. Making it easy to read the table but very difficult to read the information on regex itself.

Pros: Tables are bright and easy to read. Contains a lot of information shorthand to write regex

Cons: Information on the page is very dark and difficult to read.

Cheat Sheet 2: Regular Expressions cheat sheet – MIT

This second sheet was written by MIT. It is very spartan with no color and straight to the point on what the expressions are and what they do. This is the perfect cheat sheet if you do not want to be distracted by color or graphics. However, since it is very dry in the manner of text, I would not suggest this particular cheat sheet to someone who is just learning regular expressions since the explanations and examples are minimal.

Pros: Clean text, no colors for distraction, contains a lot of information shorthand to write regex

Cons: Too spartan for a total beginner in Regex

Cheat Sheet 3: Cheatography.com

I really love this website! This sheet was put together by Dave Child for regular expressions. It’s a nice quick reference guide pdf you can print in bright pink. It is easy to read and rated ‘E’ for everyone! It includes symbols, ranges, grouping, assertions and more with sample patterns to help get you on your way! Cheatography is one of my favorite websites for cheat sheet because they have so many on so many different topics and in many styles. It’s nice to find a one stop shop for cheat sheets.

Pros: Explains regex easily, uses soft colors, contains a lot of information.

Cons: Color may be distracting to some.

Cheat Sheet 4: Dev.to

Dev.to is a great place for new and experienced developers! This regex list was written by Catherine on her dev.to profile where she explains regex expressions in Java-script she has compiled with her resources at the bottom of here article.

Pros: Great spot to read someone else’s experience in regex and to gather new resources

Cons: More of an article than an actual pdf to print.

Cheat Sheet 5: Last Call – The Rapid API Blog

This is another great website for developers! This cheat sheet is also very easy to read and understand. It has additional resources beneath the code written. There are no examples in the post but there is shorthand explanations for each expression, characters and quantifiers. I would not suggest this particular cheat sheet for a beginner.

Pros: Great for those who understand regex and don’t have a need for examples

Ares for mac os x. Cons: Not for Beginners since it has minimal explanation

Cheat Sheet 6: GREP

Here is another one! This one is minimal in color to keep distractions down. Key words are in red and examples are done in yellow. There are minimal explanations in the color keys. This sheet is for the advanced regex user who only needs a quick reference. It is clean and easy to read. It covers all of the information needed to write your own regex!

Pros: Written cleanly, additional resources at the bottom, to the point.

Cons: Not for the regex beginner.

Cheat Sheet 7: Regex chart

Python Regex Cheat Sheet Examples Free

This Regex sheet is a very quick one with only the characters, the meaning and an example. This one is also for the advanced regex user. There is only the bare minimum here and this particular sheet does not contain quantifiers or expressions. There is a link however to a regex character classes cheat sheet.

Pros: Very quick reference of only character in regex

Cons: Not for a beginner regex user.

Cheat Sheet 8: Keycdn

Here is another awesome website to learn Regular expressions from! It goes over what regex is, gives you the list of expressions and gives you 2 separate examples on how regex is used in find numbers and emails. Near the bottom it even give you 3 tools to help you learn how to build a proper regex formula! These test sites will help you not only to build regex but compile it and make sure it running correctly before implementing it into your code.

Pros: Not only information but tools as well!

Cons: none as far I can see.

Cheat Sheet 9: MDN Web Docs

This regex syntax cheat sheet is on one of my absolute favorite places to learn about web development!! Named Moz:a (pronounced Mozilla) this particular guide will walk through not only the syntax but take you to the complete guide on regex! This cheat sheet is rated ‘E’ for everyone! It has clear examples and explanations on beginner and advanced regex characters and expressions.

Pros: Great for Everyone!!

Cons: N/A

Cheat Sheet 10: Dataquest

The final cheat sheet!! This final cheat sheet is from Dataquest. This particular cheat sheet was written specifically for Python!! This pdf is downloadable for free and explains each character and expression in detail. There is a lot of information packed in this pdf each under the proper heading and minimal color for the least number of distractions.

Pros: A lot of information pack in with minimal color.

Cons: Can appear to be overwhelming at first glance to a beginner.

I would like to thank you for taking the time to read this article. I hope that you are able to use at least one of these cheat sheets the next time you need to put a regular expression in your coding! The best way to learn though is to practice!! Good luck with writing your regex!!

Related Articles:

Related Posts

Regular expressions as a concept is not exclusive to Python at all.

Python, however, does have some nuances when it come to working with regular expressions.

This article is part of a series of articles on Python Regular Expressions.
In the first article of this series, we will focus on discussing how we work with regular expressions in python, highlighting python specifics.

We are going to introduce the methods we can use to perform queries over strings in Python. We’ll then talk about how we can use grouping to work with sub-parts of the matches we found using our queries.

The package we are interested in using to work with regular expressions in python is appropriately named ‘re’.

1. Raw Strings in Python

The python parser interprets ‘’ (backslashes) as escape characters in string literals.

If the backslash is followed by a special sequence recognized by the parser, the whole escape sequence is replaced by a corresponding special character (for example, ‘n’ is replaced by a newline character when processed by the parser).

This behavior causes a problem when working with regular expressions in python because the ‘re’ package also uses backslash characters to escape special regex characters (like * or +).

The combination of these two behaviors would mean that sometimes you would have to escape escape characters themselves (when the special character was recognized by both the python parser and the regex parser), yet other times you would not (if the special character was not recognized by the python parser).

Rather than bend our brains trying to figure out how many backslashes we need, we can instead use raw strings.

A raw string is created by simply adding an ‘r’ character before the opening quote of a normal string. When a string is raw, the python parser will not even attempt to make any substitutions within it. Essentially, you are telling the parser to completely leave your string alone.

Performing Queries with Regex in Python

The ‘re’ package provides several methods to actually perform queries on an input string. The methods that we will be discussing are:

• re.match()
• re.search()
• re.findall()

Each of the methods accepts a regular expression, and string to scan for matches. Lets take a look at each of these methods in a little more detail to see how they work and how they differ.

2. Find Using re.match – Matches Beginning

Lets first take a look at the match() method. The way the match() method works is that it will only find matches if they occur at the start of the string being searched.

So for example, calling match() on the string ‘dog cat dog’, looking for the pattern ‘dog’ will match:

We’ll be talking more about the group() method in a little bit. For now, just know that when called with 0 as it’s argument, the group() method returns the pattern matched by the query.

I’m also glossing over the returned SRE_Match object for now, we’ll talk about that in a minute too.

But, if we call match() on the same string, looking for the pattern ‘cat’, we won’t:

3. Find Using re.search – Matches Anywhere

The search() method is similar to match(), but search() doesn’t restrict us to only finding matches at the beginning of the string, so searching for ‘cat’ in our example string finds a match:

Hibernate for mac. The search() method, however, stops looking after it finds a match, so search()-ing for ‘dog’ in our example string only finds the first occurrence:

4. Get Using re.findall – All Matching Objects

The querying method that I use by far the most in python though is the findall() method. Rather than being returned match objects (we’ll talk more about match objects in a little bit), when we call findall(), we simply get a list of all matching patterns. For me, this is just simpler. Calling findall() on our example string we get:

5. Use match.start and match.end Methods

So, what exactly are these ‘match objects’ that search() and match() gave us earlier?

Rather than simply return the matching portion of the string, search() and match() return ‘matches’, which are essentially a wrapper around the matching substring.

You saw earlier that I could get to the matching substring by calling the matches group() method, (match objects are actually pretty useful when it comes to working with grouping, as we will see in the next section), but the match object also contains much more information about the matching substring.

For example, the match object can tell us the start and end indexes of the matching content from the original string:

Knowing information like this can sometimes be very useful.

6. Group by Number Using match.group

As I mentioned earlier, match objects come in very handy when working with grouping.

Grouping is the ability to address certain sub-parts of the entire regex match. We can define a group as a piece of the regular expression search string, and then individually address the corresponding content that was matched by this piece.

Let’s look at an example to see how this works:

Regex Cheat Sheet Php

The string I just created resembles a snippet taken out of someones address book. We can match the line with a regular expression like this one:

By surrounding certain parts of the regular expression in parentheses (the ‘(‘ and ‘)’ characters), we can group the content and then work with these individual groups.

Movies on mac for free. These groups can be fetched using the match object’s group() method. The groups are addressable numerically in the order that they appear, from left to right, in the regular expression (starting with group 1):

Regular Expression Cheat Sheet Python

The reason that the group numbering starts with group 1 is because group 0 is reserved to hold the entire match (we saw this earlier when we were learning about the match() and search() methods)

7. Grouping by Name Using match.group

Sometimes, especially when a regular expression has a lot of groups, it is impractical to address each group by its number. Python also allows you to assign a name to a group using the following syntax:

Regex Cheat Sheet

When can still fetch the grouped content using the group() method, but this time specifying the names we assigned the groups instead of the numbering we used before:

This makes for much more explicit and readable code. You can imagine that as the regular expression became more and more complicated, understanding what was being captured by a grouping would get harder and harder. Assigning names to your groups explicitly informs you and your readers of your intentions.

Grouping can be used with the findall() method too, even though it doesn’t return match objects. Instead, findall() will return a list of tuples, where the Nth element of each tuple corresponds to the Nth group of the regex pattern:

Perl Regex Cheat Sheet Pdf

However, named grouping doesn’t work when using the findall() method.

Python Regex Cheat Sheet Examples Download

In this article we’ve introduced the basics of working with regular expressions in Python. We’ve learned about raw strings (and the headaches that they can save you when working with regular expressions). We’ve also learned how to perform basic queries using the match(), search(), and findall() methods, and even how to work with sub-components of a match using grouping.

As always, to find out more about this topic, the Python Official documentation on re package is a great resource.

In future articles, we’ll dive deeper into regular expressions in Python. We’ll talk about how we can capture an even broader range of matches, how we can use them to make substitutions within a string, and how we can even use them to parse python data structures out of text files.