Programming Articles - Page 1871 of 3366

In this tutorial, we are going to write a program that flattens a list that contains sub-lists. Given number flatten the sublists until the given number index as parts. Let's see an example to understand it clearly.Inputlists = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]] number = 2Output[[1, 2, 3, 4], [5, 6, 7, 8], [9, 10]]Let's see the steps to solve the problem.Initialize the list and number.Initialize an empty list.Iterate over the list with range(0, len(lists), number.Get the sublists using slicing lists[i:number].Iterate over the sublists and append the resultant list to the result list.Print the result.Example# ... Read More

In this tutorial, we are going to write a program that groups all the tuples from a list that have same element as a second element. Let's see an example to understand it clearly.Input[('Python', 'tutorialspoints'), ('Management', 'other'), ('Django', 'tutorialspoints'), ('React', 'tutorialspoints'), ('Social', 'other'), ('Business', 'other')]Output{'tutorialspoint': [('Python', 'tutorialspoints'), ('Django', 'tutorialspoints'), ('React', 'tutorialspoints')], 'other’: [('Management', 'other'), ('Social', 'other'), ('Business', 'other')]}We have to group the tuples from the list. Let's see the steps to solve the problem.Initiate a list with required tuples.Create an empty dictionary.Iterate through the list of tuples.Check if the second element of the tuple is already present in the dictionary ... Read More

Grayscaling an image includes converting a color image into a grayscale image. By using OpenCV library in various methods we can convert the color image with (multiple color channels) into a grayscale image (with a single channel). Some of the common methods for greyscaling an image using OpenCV are as follows. cv2.cvtColor(): This function is used to convert an image from one space color to another. Pixel ... Read More

In this tutorial, we are going to learn how to use PostgreSQL with Python. You have to install certain thing before going into the tutorial. Let's install them.Install the PostgreSQL with the guide..Install the Python module psycopg2 for PostgreSQL connection and working. Run the command to install it.pip install psycopg2Now, open the pgAdmin. And create a sample database. Next, follow the below steps to get started with database operations.Import the psycopg2 module.Store the database name, username, and password in separate variables.Make a connection to the database using psycopg2.connect(database=name, user=name, password=password) method.Instantiate a cursor object to execute SQL commands.Create queries and ... Read More

In this tutorial, we are going to see different ways to copy a nested list in Python. Let's see one by one.First, we will copy the nested list using loops. And it's the most common way.Example Live Demo# initializing a list nested_list = [[1, 2], [3, 4], [5, 6, 7]] # empty list copy = [] for sub_list in nested_list:    # temporary list    temp = []    # iterating over the sub_list    for element in sub_list:       # appending the element to temp list       temp.append(element)    # appending the temp list to copy ... Read More

In this tutorial, we are going to find the indices of the numbers that are greater than the given number K. Let's see the different ways to find them.A most common way to solve the problem is using the loops. Let's see the steps to solve the problem.Initialize the list and K.Iterate over the list using its length.If you find any number greater than K, then print the current index.Example Live Demo# initializing the list and K numbers = [3, 4, 5, 23, 12, 10, 16] K = 10 # iterating over thAe list for i in range(len(numbers)):    # checking ... Read More

In this tutorial, we are going to write a program that finds the index of a sublist element from the list. Let's see an example to understand it clearly.Inputnested_list = [[1, 2, 3], [4, 5], [6, 7, 8, 9]]OutputIndex of 7:- 2 Index of 5:- 1 Index of 3:- 0Let's see the simple and most common way to solve the given problem. Follow the given steps solve it.Initialize the list.Iterate over the list using the index.Iterate over the sub list and check the element that you want to find the index.If we find the element then print and break itExample Live ... Read More

In this tutorial, we are going to write a program that cyclically iterates a list from the given Let's see the steps to solve the problemInitialize the list and index.Find the length of the list using len.Iterate over the list using the length.Find the index of the element using index % length.Print the element.Increment the index.It's a simple loop iteration. You can write it without any trouble. Let's see the code.Example Live Demo# initializing the list and index alphabets = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'] start_index = 5 # finding the length length = len(alphabets) # iterating over ... Read More

In this tutorial, we are going to see how to sort a list of strings. We'll sort the given list of strings with sort method and sorted function. And then we'll see how to sort the list of strings based on different criteria like length, value, etc., Let's see how to sort a list of strings using list.sort() method. The sort method list is an insort. It'll directly sort the original list. Let's see the code.Example Live Demo# list of strings strings = ['Python', 'C', 'Java', 'Javascript', 'React', 'Django', 'Spring'] # sorting the list in ascending order strings.sort() # printing the ... Read More

In this tutorial, we are going to learn about the holidays library. The holidays library will help to determine whether a particular is a holiday or not in different countries. We can only see the public holidays.Let's install the module with the following command.pip install holidaysAfter successfully installing the module follow the ways to see get the holidays information. see the holidays of India in the year 2020. You have to follow the below steps to get a complete list of holidays for India in 2020.You can find the country codes for the holidays here..Import the holidays' module.Instantiate the holidays.India() ... Read More