Python – Custom Consecutive character repetition in String

Given a String, repeat characters consecutively by number mapped in dictionary.

Input : test_str = ‘Geeks4Geeks’, test_dict = {“G” : 3, “e” : 1, “4” : 3, “k” : 5, “s” : 3} 
Output : GGGeekkkkksss444GGGeekkkkksss 
Explanation : Each letter repeated as per value in dictionary.
Input : test_str = ‘Geeks4Geeks’, test_dict = {“G” : 3, “e” : 1, “4” : 3, “k” : 5, “s” : 1} 
Output : GGGeekkkkks444GGGeekkkkks 
Explanation : Each letter repeated as per value in dictionary. 

Method #1 :  Using loop

This is one of the ways in which this task can be performed. In this, we iterate through each character and check in map its repetition and repeat for that amount.

Python3

# Python3 code to demonstrate working of
# Custom Consecutive character repetition in String
# Using loop

# initializing string
test_str = 'Geeks4Geeks'

# printing original string
print("The original string is : " + str(test_str))

# initializing dictionary
test_dict = {"G" : 3, "e" : 2, "4" : 4, "k" : 5, "s" : 3}

res = ""
for ele in test_str:

    # using * operator for repetition
    # using + for concatenation
    res += ele * test_dict[ele]

# printing result
print("The filtered string : " + str(res))

Output

The original string is : Geeks4Geeks
The filtered string : GGGeeeekkkkksss4444GGGeeeekkkkksss

Time Complexity: O(n)

Space Complexity: O(n)

Method #2 : Using list comprehension + join()

This is yet another way in which this task can be performed. In this, we perform similar task as above function. The only difference being we use join() to merge the created repetition list.

Python3

# Python3 code to demonstrate working of
# Custom Consecutive character repetition in String
# Using list comprehension + join()

# initializing string
test_str = 'Geeks4Geeks'

# printing original string
print("The original string is : " + str(test_str))

# initializing dictionary
test_dict = {"G" : 3, "e" : 2, "4" : 4, "k" : 5, "s" : 3}

# using join to perform concatenation of strings
res = "".join([ele * test_dict[ele] for ele in test_str])

# printing result
print("The filtered string : " + str(res))

Output

The original string is : Geeks4Geeks
The filtered string : GGGeeeekkkkksss4444GGGeeeekkkkksss

Time Complexity: O(n)

Space Complexity: O(n)