# Python - Character repetition string combinations

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When it is required to get the character repetitions of a given character, a method is defined that uses the index value to print the repetitions.

## Example

Below is a demonstration of the same

def to_string(my_list):
return ''.join(my_list)

def lex_recurrence(my_string, my_data, last_val, index_val):
length = len(my_string)

for i in range(length):

my_data[index_val] = my_string[i]

if index_val==last_val:
print(to_string(my_data))
else:
lex_recurrence(my_string, my_data, last_val, index_val+1)

def all_lex(my_string):
length = len(my_string)

my_data = [""] * (length+1)
my_string = sorted(my_string)
lex_recurrence(my_string, my_data, length-1, 0)

my_string = "MQ"
print("The string is :")
print(my_string)
print("All permutations with repetition of " + my_string + " are...")
all_lex(my_string)

## Output

The string is :
MQ
All permutations with repetition of MQ are...
MM
MQ
QM
QQ

## Explanation

• A method named ‘to_string’ is defined that takes a list as parameter and returns it by joining all values.

• Another method named ‘lex_recurrence’ is defined that takes a string, index values as parameter.

• It iterates over the length of the string, and checks to see if the last value and the index value are the same.

• If they are, it is printed as one of the combination.

• Otherwise, the method is called again by incrementing the value of index.

• Another method named ‘all_lex’ is defined that sorts the string using the ‘sorted’ method and calls the previous method again.

• Outside the method, a string is defined and is displayed on the console.

• The output is displayed on the console.

Updated on 21-Sep-2021 07:56:15