def get_phone_nums(worksheet, names: list) -> dict:
    """Extract phone numbers of each client into a dictionary."""

    num_rows = worksheet.max_row
    phone = {name: "" for name in names}

    for i in range(2, num_rows+1):
        name = worksheet.cell(row=i, column=1).value
        number = worksheet.cell(row=i, column=12).value

        phone[name] = number

    return phone