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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 _lowerAsn(asnfile):
 """ Create a copy of the original asn file and change the case of all members to lower-case. """

    # Start by creating a new name for the ASN table
    _indx = asnfile.find('_asn.fits')
    _new_asn = asnfile[:_indx]+'_pipeline'+asnfile[_indx:]
    if os.path.exists(_new_asn):
        os.remove(_new_asn)
    # copy original ASN table to new table
    shutil.copy(asnfile,_new_asn)

    # Open up the new copy and convert all MEMNAME's to lower-case
    fasn = fits.open(_new_asn, mode='update', memmap=False)
    for i in range(len(fasn[1].data)):
        fasn[1].data[i].setfield('MEMNAME',fasn[1].data[i].field('MEMNAME').lower())
    fasn.close()

    return _new_asn