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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def julian_day(t: date) -> int: """Convert a Python datetime to a Julian day"""

    # Compute the number of days from January 1, 2000 to date t
    dt = t - julian_base_date
    # Add the julian base number to the number of days from the julian base date to date t
    return julian_base_number + dt.days