Python – Convert Strings to Character Matrix

Sometimes, while dealing with String lists, we can have a problem in which we need to convert the Strings in list to separate character list. Overall converting into Matrix. This can have multiple applications in data science domain in which we deal with lots of data. Lets discuss certain ways in which this task can be performed.
Method #1 : Using List comprehension This is one way in which this task can be performed. In this, we convert the string to list of characters using list() and convert the result to desired matrix. 

Python3

# Python3 code to demonstrate
# Convert Strings to Character Matrix
# using List comprehension

# Initializing list
test_list = ['gfg', 'is', 'best']

# printing original list
print("The original list is : " + str(test_list))

# Convert Strings to Character Matrix
# using List comprehension
res = [list(sub) for sub in test_list]

# printing result
print ("List String after conversion to Matrix : " + str(res))

Output

The original list is : ['gfg', 'is', 'best']
List String after conversion to Matrix : [['g', 'f', 'g'], ['i', 's'], ['b', 'e', 's', 't']]

Time Complexity: O(n), where n is the length of the list test_list 
Auxiliary Space: O(n) additional space of size n is created where n is the number of elements in the res list

Method #2 : Using loop + list() This is brute force way to perform this task. In this, we run loop and convert each string to character list using list(). 

Python3

# Python3 code to demonstrate
# Convert Strings to Character Matrix
# using loop + list()

# Initializing list
test_list = ['gfg', 'is', 'best']

# printing original list
print("The original list is : " + str(test_list))

# Convert Strings to Character Matrix
# using loop + list()
res = []
for sub in test_list:
    res.append(list(sub))

# printing result
print ("List String after conversion to Matrix : " + str(res))

Output

The original list is : ['gfg', 'is', 'best']
List String after conversion to Matrix : [['g', 'f', 'g'], ['i', 's'], ['b', 'e', 's', 't']]

Method #3 :  Here’s another approach using the map function:

Python3

# Python3 code to demonstrate
# Convert Strings to Character Matrix
# using map()

# Initializing list
test_list = ['gfg', 'is', 'best']

# printing original list
print("The original list is : " + str(test_list))

# Convert Strings to Character Matrix
# using map()
res = list(map(list, test_list))

# printing result
print ("List String after conversion to Matrix : " + str(res))
#This code is contributed by Edula Vinay Kumar Reddy

Output

The original list is : ['gfg', 'is', 'best']
List String after conversion to Matrix : [['g', 'f', 'g'], ['i', 's'], ['b', 'e', 's', 't']]

Time Complexity: O(n) where n is the length of the test_list.
Auxiliary Space: O(n) as we are creating a new list res to store the result.

Explanation: In this approach, we use the map function to apply the list function to each element of the test_list and store the result in the res list.