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Extracting only the numbers from a text is a very common requirement in python data analytics. It is done easily using the python regular expression library. This library helps us define the patterns for digits which can be extracted as substrings.ExamplesIn the below example we use the function findall() from the re module. The parameters to these function are the pattern which we want to extract and the string from which we want to extract. Please note with below example we get only the digits and not the decimal points or the negative signs.import re str=input("Enter a String with numbers: ... Read More
In any programming language we find a situation where exceptions are raised. Python has many inbuilt exception handling mechanisms. There are errors which are handled by this exception names. Python also has a block called finally which is executed irrespective of whether the exception is handled or not.Syntaxtry: # main python Code.... except: # It is optional block # Code to handle exception finally: # This Code that is always executedExampleIn the below code we see an exception called NameError. Here we create a code which refers to undeclared variables. Even though the exception is handled ... Read More
Lists are the most frequently used data structures of python. When we want to add more elements to a list, the extension of list happens. This can be done in following 5 different ways.Using the Plus operatorHere we simply add the elements of a new list using the + operator. The behavior is similar to how we modify the values of a variable.Exampleslist = ['Mon', 'Tue', 'Wed'] list = list + ['Thu', 'Fri'] print(list)OutputRunning the above code gives us the following result −['Mon', 'Tue', 'Wed', 'Thu', 'Fri']Using SlicingWe can use slicing to add elements at the end of a list. ... Read More
The divmod() is part of python’s standard library which takes two numbers as parameters and gives the quotient and remainder of their division as a tuple. It is useful in many mathematical applications like checking for divisibility of numbers and establishing if a number is prime or not.SyntaxSyntax: divmod(a, b) a and b : b divides a a and b are integers or floatsExamplesIn the below example see the cases of both integers and floats. On the application of divmod() they give us a resulting tuple which is can also contain integers and float values.# with integers print("5 and 2 ... Read More
Clearing up all the elements in a python list can be done in many ways. Below are the some of the methods which are implemented to achieve this.using clear()This function is a part of standard library and empties the python list completely.Syntax: list_name.clear() list_name is the name of the list supplied byExampleIn the below example we take a list and apply the clear (). The result is an empty list.list = ['Mon', 'Tue', 'Wed', 'Thu'] print("Existing list", list) #clear the list list.clear() print("After clearing the list") print(list)OutputRunning the above code gives us the following result −Existing list ['Mon', 'Tue', 'Wed', ... Read More
In this article, we will learn about Logic Gates in Python. Let’s look at each of the logic gates in Python in detail with some easy examples.All of us are quite familiar while implementing logic gates in the processing of electrical signals and are widely used in the electrical and electronics industry. They are used in the diodes and transistors so that we can design by proper alignment of these electronic devices. In this article we will learn about the implementation of some basic gates ‘and‘, ‘or‘ ,’not‘ , ‘nand‘ ,’nor‘ in Python 3.x or earlier.These gates can be implemented ... Read More
These two functions are used to remove attributes from classes. The delattr() allows dynamoc deletion of attribute while the del() is more efficient explicit in deleting the attribute.Using delattr()Syntax: delattr(object_name, attribute_name) Where object name is the name of the object, instantiated form the class. Attribute_name is the name of the attribute to be deleted.ExampleIn the below example we consider a class named custclass. It has the id of the customers as its attributes. Next we instantiate the class as an object named customer and print its attriutes.class custclass: custid1 = 0 custid2 = 1 custid3 = 2 ... Read More
In this article, we will learn about a program in which we can remove an all characters other than alphabets using the concept of list comprehension and ord() function in Python 3.x. Or earlier.Algorithm1.We Traverse the given string to check the charater. 2.Selection of characters is done which lie in the range of either [a-z] or [A-Z]. 3.Using the join function we print all the characters which pass the test together.Exampledef remchar(input): # checking uppercase and lowercase characters final = [ch for ch in input if (ord(ch) in range(ord('a'), ord('z')+1, 1)) or (ord(ch) in range(ord('A'), ord('Z')+1, 1))] return ... Read More
As python allows duplicate elements in a list we can have one element present multiple Times. The frequency of elements in a list indicates how many times an element occurs in a list. In this article we use the Counter function of the collections module to find out the frequency of each item in a list.SyntaxSyntax: Counter(list) Where list is an iterable in pythonExampleThe below code uses the Counter() to keep track of frequency and items() to iterate over each item in the result of counter function for printing in a formatted manner.from collections import Counter list = ['Mon', 'Tue', ... Read More
In a list in Python we may have duplicate elements. When we count the length of the list we get the total length including the duplicate elements. But in this article we will see how to get the total count of the distinct elements or unique elements in a list.ExampleIn the below example we use the counter() from the collections module. In this module a Counter is a dict subclass for counting hashable objects. Counter is an unordered collection where elements are stored as dictionary keys and their counts are stored as dictionary values. So from the original list we ... Read More