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# Python – Custom Consecutive character repetition in String

• Last Updated : 20 Aug, 2022

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)

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