Python NumPy Practice Exercises, Questions, and Solutions (original) (raw)

Python Matrix Exercises

• Python program to a Sort Matrix by index-value equality count Given a Matrix, the task is to write a Python program that can sort its rows or columns on a measure of the number of values equal to its index number. For each row or column, count occurrences of equality of index number with value. After computation of this count for each row or column, sort the m 6 min read

• Python Program to Reverse Every Kth row in a Matrix We are given a matrix (a list of lists) and an integer K. Our task is to reverse every Kth row in the matrix. For example: Input : a = [[5, 3, 2], [8, 6, 3], [3, 5, 2], [3, 6], [3, 7, 4], [2, 9]], K = 4 Output : [[5, 3, 2], [8, 6, 3], [3, 5, 2], [6, 3], [3, 7, 4], [2, 9]]Using reversed() and loopWe 5 min read

• Python Program to Convert String Matrix Representation to Matrix Given a String with matrix representation, the task here is to write a python program that converts it to a matrix. Input : test_str = "[gfg,is],[best,for],[all,geeks]"Output : [['gfg', 'is'], ['best', 'for'], ['all', 'geeks']]Explanation : Required String Matrix is converted to Matrix with list as 4 min read

• Python - Count the frequency of matrix row length Given a Matrix, the task is to write a Python program to get the count frequency of its rows lengths. Input : test_list = [[6, 3, 1], [8, 9], [2], [10, 12, 7], [4, 11]] Output : {3: 2, 2: 2, 1: 1} Explanation : 2 lists of length 3 are present, 2 lists of size 2 and 1 of 1 length is present. Input : 5 min read

• Python - Convert Integer Matrix to String Matrix Given a matrix with integer values, convert each element to String. Input : test_list = [[4, 5, 7], [10, 8, 3], [19, 4, 6]] Output : [['4', '5', '7'], ['10', '8', '3'], ['19', '4', '6']] Explanation : All elements of Matrix converted to Strings. Input : test_list = [[4, 5, 7], [10, 8, 3]] Output : [ 6 min read

• Python Program to Convert Tuple Matrix to Tuple List Given a Tuple Matrix, flatten to tuple list with each tuple representing each column. Example: Input : test_list = [[(4, 5), (7, 8)], [(10, 13), (18, 17)]] Output : [(4, 7, 10, 18), (5, 8, 13, 17)] Explanation : All column number elements contained together. Input : test_list = [[(4, 5)], [(10, 13)] 8 min read

• Python - Group Elements in Matrix Given a Matrix with two columns, group 2nd column elements on basis of 1st column. Input : test_list = [[5, 8], [2, 0], [5, 4], [2, 3], [2, 9]] Output : {5: [8, 4], 2: [0, 3, 9]} Explanation : 8 and 4 are mapped to 5 in Matrix, all others to 2. Input : test_list = [[2, 8], [2, 0], [2, 4], [2, 3], [2 6 min read

• Python - Assigning Subsequent Rows to Matrix first row elements Given a (N + 1) * N Matrix, assign each column of 1st row of matrix, the subsequent row of Matrix. Input : test_list = [[5, 8, 10], [2, 0, 9], [5, 4, 2], [2, 3, 9]] Output : {5: [2, 0, 9], 8: [5, 4, 2], 10: [2, 3, 9]} Explanation : 5 paired with 2nd row, 8 with 3rd and 10 with 4th Input : test_list 3 min read

• Adding and Subtracting Matrices in Python In this article, we will discuss how to add and subtract elements of the matrix in Python. Example: Suppose we have two matrices A and B. A = [[1,2],[3,4]] B = [[4,5],[6,7]] then we get A+B = [[5,7],[9,11]] A-B = [[-3,-3],[-3,-3]] Now let us try to implement this using Python 1. Adding elements of t 4 min read

• Python - Convert Matrix to Dictionary The task of converting a matrix to a dictionary in Python involves transforming a 2D list or matrix into a dictionary, where each key represents a row number and the corresponding value is the row itself. For example, given a matrix li = [[5, 6, 7], [8, 3, 2], [8, 2, 1]], the goal is to convert it i 4 min read

• Python - Convert Matrix to Custom Tuple Matrix Sometimes, while working with Python Matrix, we can have a problem in which we need to perform conversion of a Python Matrix to matrix of tuples which a value attached row-wise custom from external list. This kind of problem can have applications in data domains as Matrix is integral DS that is used 6 min read

• Python - Matrix Row subset Sometimes, while working with Python Matrix, one can have a problem in which, one needs to extract all the rows that are a possible subset of any row of other Matrix. This kind of problem can have applications in data domains as a matrix is a key data type in those domains. Let's discuss certain way 7 min read

• Python - Group similar elements into Matrix Sometimes, while working with Python Matrix, we can have a problem in which we need to perform grouping of all the elements with are the same. This kind of problem can have applications in data domains. Let's discuss certain ways in which this task can be performed. Input : test_list = [1, 3, 4, 4, 8 min read

• Python - Row-wise element Addition in Tuple Matrix Sometimes, while working with Python tuples, we can have a problem in which we need to perform Row-wise custom elements addition in Tuple matrix. This kind of problem can have application in data domains. Let's discuss certain ways in which this task can be performed. Input : test_list = [[('Gfg', 3 4 min read

• Create an n x n square matrix, where all the sub-matrix have the sum of opposite corner elements as even Given an integer N. The task is to generate a square matrix of ( n x n ) having the elements ranging from 1 to n^2 with the following condition: The elements of the matrix should be distinct i.e used only onceNumbers ranging from 1 to n^2Every sub-matrix you choose should have the sum of opposite co 6 min read