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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 compute_texptime(imageObjectList):
 """ Add up the exposure time for all the members in the pattern, since 'drizzle' doesn't have the necessary information to correctly set this itself. """

    expnames = []
    exptimes = []
    start = []
    end = []
    for img in imageObjectList:
        expnames += img.getKeywordList('_expname')
        exptimes += img.getKeywordList('_exptime')
        start += img.getKeywordList('_expstart')
        end += img.getKeywordList('_expend')

    exptime = 0.
    expstart = min(start)
    expend = max(end)
    exposure = None
    for n in range(len(expnames)):
        if expnames[n] != exposure:
            exposure = expnames[n]
            exptime += exptimes[n]

    return (exptime,expstart,expend)