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In this article, we are going to learn how to extract a URL from an HTML link using Python regular expressions. URL is an acronym for Uniform Resource Locator; it is used to identify the location resource on the Internet. URL consists of a domain name, path, port number, etc. The URL can be parsed and processed by using a Regular Expression. Therefore, if we want to use a Regular Expression, we have to use the "re" library in Python. Following is an example of a URL - URL: https://www.tutorialspoint.com/courses If we parse the above URL we can find ... Read More
In this article, you will find out how to use the range in Python regular expressions. With the help of Python's regular expressions, you can search, match, and manipulate text efficiently. One useful feature in regex is ranges, so it helps us define sets of characters within square brackets "[ ]". Range in Regex In Python, a range is used when you want to match characters within a specific group. It is defined inside brackets "[ ]" with the help of a hyphen -. For example: # Matches any digit (0 to 9) pat1 = r"[0-9]" ... Read More
This article will explain how to write a Python regular expression to use re.findall() method. Regular expression, or regex, is used insearching and extracting patterns in text. Python provides the re module to work with regex, and re.findall() to find all matches of a pattern in a string. The re.findall() method returns a list of all occurrences of a pattern. It works with strings for extracting data. And it supports metacharacters for pattern matching. There are various ways to use the re.findall() method in Python, such as - Finds One or More Digits Find All Words in a String Extract ... Read More
Backslashes in Python regular expressions (regex) are used to define special sequences and escape characters. As backslashes are also used in Python strings, we need to be careful while using them. How Backslashes Work Now let us see how backslashes work in Python regular expressions - Escaping Characters: Some characters have specific meanings in regex (such as . or *). To treat them as normal characters, use a backslash (\.). ... Read More
This article gives a guide on the difference between re.findall() and re.finditer() methods available in Python. The re module of Python helps in working with regular expressions. Both the re.findall() and re.finditer() methods are used to search for patterns, but they behave differently. Let us see the differences with simple explanations and examples in this article. Using re.findall() Method The re.findall() helps to get a list of all matching patterns. It searches from the start or end of the given string. If we use the findall() method to search for a pattern in a given string, it will return all occurrences ... Read More
Python offers many built-in data structures like lists, tuples, sets, and dictionaries, which are used to store and manage data easily. In this article, we will discuss the difference between a Python tuple and a dictionary. Tuple Tuples are a data type that belongs to the sequence data type category. They are similar to lists in Python, but they are immutable. We can't change the elements of a tuple, but we can execute a variety of actions on them, such as count, index, type, etc. Tuples are created in Python by placing a sequence of values separated by a 'comma', with or ... Read More
The functors are the function objects in C++. The functor allows an instance object of some class to be called as if it were an ordinary function. Let us consider a function that takes one argument. We can use this function as function object to do some task on a set of data. The Functors are widely used in STL algorithms like transform(), sort(), etc. Functor vs Regular Function: Need of Functor? Imagine we have a function that takes only one argument, like this: int increment(int x) { return x + 1; } Now, what ... Read More
When something goes wrong in Python, it shows a message called exception text that explains the error. You can save and use this text in your program to help with logging or fixing the problem later. You can get Python exception text using str() function, traceback module, logging, or the args attribute. This allows you to log, debug, or display user-friendly error messages in your programs. Using str() Function The easiest way to get the exception text is by converting the exception object to a string using the str() function. This returns the error message associated with the exception. Example ... Read More
In Python, exceptions are not just error messages; they are actual objects. Understanding that exceptions are objects helps you work with them more effectively, such as accessing their attributes or creating custom exceptions. What do We mean by Exception is an Object? When an exception occurs, Python creates an instance of an exception class. This instance contains information about the error, like its type, message, and traceback. Since exceptions are objects, you can interact with them just like any other Python object. Example: Catching an exception object In the following example, we catch a ZeroDivisionError and assign it to a ... Read More
Whenever Python comes across a variable or name that is not defined in the local or global namespace, it raises a NameError. This helps in debugging and ensures that variables are properly declared before using it. There are various ways to catch and handle a NameError in Python. The most common method is using a try-except block. Below are different approaches to catch a NameError exception - Using try-except block with NameError Using try-except-else block Using try-except-finally block Using try-except Block with NameError In Python, you ... Read More