Python | Nth Column vertical string in Matrix
Sometimes, while working with Python Matrix, we can have a problem in which we need to access the Matrix in vertical form and extract strings from same, that too as a string, not merely as a list of characters. This task has it’s application in gaming in which we need to extract string during crosswords. Let’s discuss a way in which this task can be performed.
Method : Using list comprehension + join() We achieve the task in this method in 2 steps. In 1st step the Nth column elements are extracted using list comprehension. In 2nd step, these elements are joined together to perform the characters to string conversion.
The original list : [('a', 'g', 'v'), ('e', 'f', 8), ('b', 'g', 0)] Constructed vertical string : gfg
Method : Using numpy()
Note: Install numpy module using command “pip install numpy”
Another approach could be using numpy, which can extract the Nth column of a matrix as a numpy array and then use numpy.array2string() to convert the array to a string. This approach would have a time complexity of O(n) where n is the number of rows in the matrix, and a space complexity of O(n) as well, as it requires a new numpy array to be created.
Constructed vertical string : gfg
This approach using numpy would have O(n) time complexity and O(n) Auxiliary space as well.