【Python】gspreadなどを使う時にセルを数値からアルファベット形式（A1 notation）に加工する

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def to_alpha_under_3digits(number : int) -> str:
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    """
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    Number of cell this method can format is 26 x 26 x 27 = 18252.
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    """
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    number_of_alphabet = 26
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    h = int((number - 1 - number_of_alphabet) / (number_of_alphabet * number_of_alphabet))
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    i = int((number - 1) / number_of_alphabet) - h * number_of_alphabet
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    j = number - (i * number_of_alphabet) - (h * number_of_alphabet * number_of_alphabet)
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    alpha = ""
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    for k in h, i, j:
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        if k != 0:
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            alpha += chr(k + 64)
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    return alpha
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def get_cell_in_a1_notation(row_index : int, col_index : int) -> str:
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    con_index_alpha =to_alpha_under_3digits(col_index)
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    cell = "{1}{0}".format(str(row_index), str(con_index_alpha))
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    return cell
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def get_range_in_a1_notation(start_row_index : int, start_col_index : int, num_rows : int, num_cols : int) -> str:
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    start_cell = get_cell_in_a1_notation(start_row_index, start_col_index)
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    end_row_index = start_row_index + num_rows - 1
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    end_col_index = start_col_index + num_cols - 1
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    end_cell = get_cell_in_a1_notation(end_row_index, end_col_index)
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    return "{}:{}".format(start_cell, end_cell)
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alpha_1 = to_alpha_under_3digits(1)
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alpha_2 = to_alpha_under_3digits(26)
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alpha_3 = to_alpha_under_3digits(29)
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alpha_4 = to_alpha_under_3digits(16784)
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print(alpha_1)
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print(alpha_2)
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print(alpha_3)
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print(alpha_4)
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print("==============")
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cell_1 = get_cell_in_a1_notation(1, 1)
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cell_2 = get_cell_in_a1_notation(10, 26)
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cell_3 = get_cell_in_a1_notation(15, 29)
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print(cell_1)
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print(cell_2)
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print(cell_3)
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print("==============")
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range_1 = get_range_in_a1_notation(1, 1, 10, 26)
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range_2 = get_range_in_a1_notation(10, 26, 15, 29)
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range_3 = get_range_in_a1_notation(15, 29, 20, 16784)
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print(range_1)
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print(range_2)
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print(range_3)