Concatenation of Consecutive Binary Numbers LeetCode solution in Python

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class Solution:
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    def concatenatedBinary(self, n: int) -> int:
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        modulo = 10**9 + 7
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        shift = 0  # tracking power of 2
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        res = 0
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        for i in range(1, n + 1):
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            if i & (i - 1) == 0:  # see if num reaches a greater power of 2
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                shift += 1
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            res = ((res << shift) + i) % modulo  # do the simulation
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        return res