Count Number of Homogenous Substrings LeetCode solution in Python

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# Runtime: 127 ms (Top 59.9%) | Memory: 17.38 MB (Top 67.5%)
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class Solution:
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    def countHomogenous(self, s: str) -> int:
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        res, count, n = 0, 1, len(s)
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        for i in range(1, n):
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            if s[i] == s[i - 1]:
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                count += 1
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            else:
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                if count > 1:
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                    res += count * (count - 1) // 2
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                count = 1
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        if count > 1:
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            res += count * (count - 1) // 2
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        return (res + n) % (10**9 + 7)