Programming Articles - Page 600 of 3363

The range() method in Python is used to return a sequence object. It is used in Python 3.x The xrange() is used to generate sequence of number and used in Python 2.x. Therefore, there’s no xrange() in Python 3.x. Let us first learn about range() and xrange() one by one. The range() method in Python The range() method returns a sequence of numbers and has 3 parameters i.e. start, stop and step. Here’s the syntax − range(start, stop, step) Here, start − Integer specifying at which position to start. stop − Integer specifying at which position to stop. ... Read More

In Python, if you want to copy object, the assignment operator won’t fulfil the purpose. It creates bindings between a target and an object i.e., it never creates a new object. It only creates a new variable sharing the reference of the original object. To fix this, the copy module is provided. This module has generic shallow and deep copy operations. Shallow Copy A shallow copy constructs a new compound object and then inserts references into it to the objects found in the original. It uses the following method to copy objects  − copy.copy(x) Return a shallow copy of x. ... Read More

The arrays in Python are ndarray objects. The matrix objects are strictly 2-dimensional whereas the ndarray objects can be multi-dimensional. To create arrays in Python, use the Numpy library. Matrices in Python Matrix is a special case of two-dimensional array where each data element is of strictly same size. Matrices are a key data structure for many mathematical and scientific calculations. Every matrix is also a two-dimensional array but not vice versa. Matrix objects are a subclass of ndarray, so they inherit all the attributes and methods of ndarrays. Example Create a Matrix and Display from numpy import * ... Read More

We will display the contents of a text file in reverse order. For that, let us first create a text file amit.txt with the following content  Display the contents of a text file in Reverse Order with Slicing Example Let us now read the contents of the above file in reverse order − # The file to be read with open("amit.txt", "r") as myfile: my_data = myfile.read() # Reversing the data by passing -1 for [start: end: step] rev_data = my_data[::-1] # Displaying the reversed data print("Reversed data = ", rev_data) Output Reversed ... Read More

Let us understand what is Del and Remove() in a Python List before moving towards the difference. Del Keyword in Python List The del keyword in Python is used to remove an element or multiple elements from a List. We can also remove all the elements i.e. delete the entire list. Example Delete an element from a Python List using the del keyword #Create a List myList = ["Toyota", "Benz", "Audi", "Bentley"] print("List = ", myList) # Delete a single element del myList[2] print("Updated List = ", myList) Output List = ['Toyota', 'Benz', 'Audi', 'Bentley'] Updated ... Read More

In this article, we will implement various example to replace all occurrences of a substring with a new string. Let’s say we have the following string − Hi, How are you? How have you been? We have to replace all occurrences of substring “How “ with “Demo”. Therefore, the output should be − Hi, Demo are you? Demo have you been? Let us now see some examples − Replace All Occurrences of a Python Substring with a New String using replace() Example In this example, we will use the replace() method to replace all occurrences of a Python Substring with ... Read More

Python Sequences includes Strings, Lists, Tuples, etc. We can merge elements of a Python sequence using different ways. Merge Elements in a Python List Example The join() method is used to merge elements − # List myList = ['H', 'O', 'W', 'A', 'R', 'E', 'Y', 'O', 'U'] # Display the List print ("List = " + str(myList)) # Merge items using join() myList[0 : 3] = [''.join(myList[0 : 3])] # Displaying the Result print ("Result = " + str(myList)) Output List = ['H', 'O', 'W', 'A', 'R', 'E', 'Y', 'O', 'U'] Result = ['HOW', 'A', 'R', ... Read More

To check if all the characters in a string are alphanumeric, we can use the isalnum() method in Python and Regex also. First, let us understand what is alphanumeric. What is Alphanumeric? Alphanumeric includes both letters and numbers i.e., alphabet letter (a-z) and numbers (0-9). Examples: A, a, k, K, 8, 10, 20, etc. Let us see an example of an Alphanumeric string 8k9q2i3u4t Let us see an example of a string wherein all the characters aren’t Alphanumeric - $$###k9q2i3u4t Check If All the Characters in a String Are Alphanumeric using isalnum() We will use the built-in isalnum() ... Read More

In Python, the // is the double slash operator i.e. Floor Divison. The // operator is used to perform division that rounds the result down to the nearest integer. The usage of the // operator is quite easy. We will also compare the results with single slash division. Let us first see the syntax: Syntax of // (double slash) Operator The a and b are 1st and 2nd number: a // b Example of // (double slash) Operator Let us now see an example to implement the double slash operator in Python - a = 37 b = 11 ... Read More

To serialize and de-serialize a Python object structure, we have the Pickle module in Python. The pickle module implements binary protocols for serializing and de-serializing a Python object structure. Pickling is the process through which a Python object hierarchy is converted into a byte stream. To serialize an object hierarchy, you simply call the dumps() function. Unpickling is the inverse operation. A byte stream from a binary file or bytes-like object is converted back into an object hierarchy. To de-serialize a data stream, you call the loads() function. Pickling and unpickling are alternatively known as serialization. What can be pickled ... Read More