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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 _process_json(data):
 """ return a list of GradPetition objects. """

    requests = []
    for item in data:
        petition = GradPetition()
        petition.description = item.get('description')
        petition.submit_date = parse_datetime(item.get('submitDate'))
        petition.decision_date = parse_datetime(item.get('decisionDate'))

        if item.get('deptRecommend') and len(item.get('deptRecommend')):
            petition.dept_recommend = item.get('deptRecommend').lower()

        if item.get('gradSchoolDecision') and\
           len(item.get('gradSchoolDecision')):
            petition.gradschool_decision =\
                item.get('gradSchoolDecision').lower()
        requests.append(petition)
    return requests