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Python Functional Python The Lambda Lambada Recursion

Andy McDonald
Andy McDonald
5,016 Points

Calling the function within the function

This part is really hard for me to conceptualize, to run the function again an return new values. I figure I have to call it based upon the values I got on the first time around but I'm not sure how to turn the function on those items within the items in the dict. I just really don't know the syntax for doing that.

courses.py
courses = {'count': 2,
           'title': 'Django Basics',
           'prereqs': [{'count': 3,
                     'title': 'Object-Oriented Python',
                     'prereqs': [{'count': 1,
                               'title': 'Python Collections',
                               'prereqs': [{'count':0,
                                         'title': 'Python Basics',
                                         'prereqs': []}]},
                              {'count': 0,
                               'title': 'Python Basics',
                               'prereqs': []},
                              {'count': 0,
                               'title': 'Setting Up a Local Python Environment',
                               'prereqs': []}]},
                     {'count': 0,
                      'title': 'Flask Basics',
                      'prereqs': []}]}


def prereqs(data, pres=None):
    pres = pres or set()
    for pre in data['prereqs']:
        pres.add(pre['title'])
    for i in pres:
        prereqs(data['title'=i])

    return pres
Chris Freeman
Chris Freeman
Treehouse Moderator 67,636 Points

Check out a previous answer I gave on thinking through the recursion. Let me know if you need further help. Gook luck!!

1 Answer