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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 sfiles_to_event(sfile_list):
 """ Write an event.dat file from a list of Seisan events :type sfile_list: list :param sfile_list: List of s-files to sort and put into the database :returns: List of tuples of event ID (int) and Sfile name """

    event_list = []
    sort_list = [(readheader(sfile).origins[0].time, sfile)
                 for sfile in sfile_list]
    sort_list.sort(key=lambda tup: tup[0])
    sfile_list = [sfile[1] for sfile in sort_list]
    catalog = Catalog()
    for i, sfile in enumerate(sfile_list):
        event_list.append((i, sfile))
        catalog.append(readheader(sfile))
    # Hand off to sister function
    write_event(catalog)
    return event_list