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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 combine_recs(rec_list, key):
 """Use a common key to combine a list of recs"""

    final_recs = {}
    for rec in rec_list:
        rec_key = rec[key]
        if rec_key in final_recs:
            for k, v in rec.iteritems():
                if k in final_recs[rec_key] and final_recs[rec_key][k] != v:
                    raise Exception("Mis-match for key '%s'" % k)
                final_recs[rec_key][k] = v
        else:
            final_recs[rec_key] = rec
    return final_recs.values()