comefrom: <doocs>1456.Maximum Number of Vowels in a Substring of Given Length_1.py
code: def maxVowels( s: str, k: int) -> int:
      vowels = set('aeiou')
      t = sum(c in vowels for c in s[:k])
      ans = t
      for i in range(k, len(s)):
          t += s[i] in vowels
          t -= s[i - k] in vowels
          ans = max(ans, t)
      return ans
masked: def sample_funcname ( var_0 : str , var_1 : int ) -> int :
      var_2 = set ( 'aeiou' )
      var_4 = sum ( var_3 in var_2 for var_3 in var_0 [ : var_1 ] )
      var_5 = var_4
      for var_6 in range ( var_1 , len ( var_0 ) ) :
          var_4 += var_0 [ var_6 ] in var_2
          var_4 -= var_0 [ var_6 - var_1 ] in var_2
          var_5 = max ( var_5 , var_4 )
      return var_5
  