[Solved] To find number of continuous Repeating characters

Question

Hints

I would follow this steps:

Create a list where I will store my partial strings
Start iterating the string
- Store the initial position and the current character
- Keep iterating until the character is different
- Store in the list the partial string from the initial position you stored until 1 less than the current position
- Update the initial position to the current one and the current character
Use the list to create a collections.Counter

About your code, the_string[i] == the_string[i] will always be true.

SPOILER: solution

from collections import Counter


def repeating_letters(the_string):
    partials = []
    initial = 0
    for i, character in enumerate(the_string):
        if character == the_string[initial]:
            continue
        partials.append(the_string[initial:i])
        initial = i
    partials.append(the_string[initial:])  # Needed for the last partial string
    return Counter(partials)

As @prahantrana mentions in a comment, getting the partials can be done in a one-liner with the groupby method from the itertools library.

from collections import Counter
from itertools import groupby


def repeating_letters(the_string):
    return Counter(''.join(group) for _, group in groupby(the_string))

Or

from collections import Counter
from itertools import groupby


def repeating_letters(the_string):
    return Counter(char*len(list(group)) for char, group in groupby(the_string))

I’m not sure which of them is faster.

Accepted Answer