Maximum Number of Vowels in a Substring of Given Length LeetCode solution in Python

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class Solution:
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    def maxVowels(self, s: str, k: int) -> int:
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        def find_count_vowels(string):
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            lst_vowels = ["a", "e", "i", "o", "u"]
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            c = 0
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            for i in string:
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                if i in lst_vowels:
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                    c += 1
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            return c
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        lst_vowels = ["a", "e", "i", "o", "u"]
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        if k > len(s):
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            return find_count_vowels(s)
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        dp = [0] * (len(s) - k + 1)
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        dp[0] = find_count_vowels(s[:k])
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        for i in range(1, len(s) - k + 1):
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            if s[i - 1] in lst_vowels and s[i + k - 1] in lst_vowels:
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                dp[i] = dp[i - 1]
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            elif s[i - 1] in lst_vowels and s[i + k - 1] not in lst_vowels:
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                dp[i] = dp[i - 1] - 1
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            elif s[i - 1] not in lst_vowels and s[i + k - 1] in lst_vowels:
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                dp[i] = dp[i - 1] + 1
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            else:
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                dp[i] = dp[i - 1]
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        return max(dp)