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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 str2et(time):
 """ Convert a string representing an epoch to a double precision value representing the number of TDB seconds past the J2000 epoch corresponding to the input epoch. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/str2et_c.html :param time: A string representing an epoch. :type time: str :return: The equivalent value in seconds past J2000, TDB. :rtype: float """

    if isinstance(time, list):
        return numpy.array([str2et(t) for t in time])
    time = stypes.stringToCharP(time)
    et = ctypes.c_double()
    libspice.str2et_c(time, ctypes.byref(et))
    return et.value