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!! This cheat sheets will be a great reference when you need to put them in your scripts when …
Regular expressions are a strange animal. Many students find them difficult to understand – do you? I realized that a major reason for this is simply that they don’t understand the special regex characters. To put it differently: understand the special characters and everything else in the regex space will come much easier to you. …
Regex Special Characters – Examples in Python Re Read More »
If you’re like me, you’ll regularly sit in front of your code and wonder: how to escape a given character? Challenge: Some characters have a special meaning in Python strings and regular expressions. Say you want to to search for string “(s)” but the regex engine takes the three characters (s) as a matching group. …
You can create an iterable of all pattern matches in a text by using the re.finditer(pattern, text) method: Specification: re.finditer(pattern, text, flags=0) Definition: returns an iterator that goes over all non-overlapping matches of the pattern in the text. The flags argument allows you to customize some advanced properties of the regex engine such as whether …
To count a regex pattern multiple times in a given string, use the method len(re.findall(pattern, string)) that returns the number of matching substrings or len([*re.finditer(pattern, text)]) that unpacks all matching substrings into a list and returns the length of it as well. A few hours ago, I wrote a regular expression in Python that matched …
Python Regex – How to Count the Number of Matches? Read More »
Just like me an hour ago, you’re probably sitting in front of your regular expression code, puzzled by a strange error message: Why is it raised? Where does it come from? And, most importantly, how can you get rid of it? This article gives you answers to all of those questions. Alternatively, you can also …
When I first learned about regular expressions, I didn’t really appreciate their power. But there’s a reason regular expressions have survived seven decades of technological disruption: coders who understand regular expressions have a massive advantage when working with textual data. They can write in a single line of code what takes others dozens! This article …
Python re.findall() – Everything You Need to Know Read More »
Why have regular expressions survived seven decades of technological disruption? Because coders who understand regular expressions have a massive advantage when working with textual data. They can write in a single line of code what takes others dozens! This article is all about the re.match() method of Python’s re library. There are two similar methods to …
Why have regular expressions survived seven decades of technological disruption? Because coders who understand regular expressions have a massive advantage when working with textual data. They can write in a single line of code what takes others dozens! This article is all about the re.fullmatch(pattern, string) method of Python’s re library. There are three similar methods …
The method re.compile(pattern) returns a regular expression object from the pattern that provides basic regex methods such as pattern.search(string), pattern.match(string), and pattern.findall(string). The explicit two-step approach of (1) compiling and (2) searching the pattern is more efficient than calling, say, search(pattern, string) at once, if you match the same pattern multiple times because it avoids …
In many Python regex functions, you see a third argument flags. What are they and how do they work? Flags allow you to control the regular expression engine. Because regular expressions are so powerful, they are a useful way of switching on and off certain features (e.g. whether to ignore capitalization when matching your regex). …
I’m always surprised how regular expressions survived seven decades of technological disruption. They look much the same as 70 years ago. This means that if you master regular expressions, you build yourself a lasting and highly relevant skill in today’s marketplace. You’ll be able to write in a single line of code what takes others …
