17_Family Tree.py

# Single Gold Star

# Family Trees

# In the lecture, we showed a recursive definition for your ancestors. For this
# question, your goal is to define a procedure that finds someone's ancestors,
# given a Dictionary that provides the parent relationships.

# Here's an example of an input Dictionary:

#

ada_family = { 'Judith Blunt-Lytton': ['Anne Isabella Blunt', 'Wilfrid Scawen Blunt'],
              'Ada King-Milbanke': ['Ralph King-Milbanke', 'Fanny Heriot'],
              'Ralph King-Milbanke': ['Augusta Ada King', 'William King-Noel'],
              'Anne Isabella Blunt': ['Augusta Ada King', 'William King-Noel'],
              'Byron King-Noel': ['Augusta Ada King', 'William King-Noel'],
              'Augusta Ada King': ['Anne Isabella Milbanke', 'George Gordon Byron'],
              'George Gordon Byron': ['Catherine Gordon', 'Captain John Byron'],
              'John Byron': ['Vice-Admiral John Byron', 'Sophia Trevannion'] }

# Define a procedure, ancestors(genealogy, person), that takes as its first input
# a Dictionary in the form given above, and as its second input the name of a
# person. It should return a list giving all the known ancestors of the input
# person (this should be the empty list if there are none). The order of the list
# does not matter and duplicates will be ignored.

def ancestors(genealogy, person):

    family=[]

    if person not in genealogy:
        return family
    else:
        for parent in genealogy[person]:
            family.append(parent)
            family+=ancestors(genealogy,parent)
        return family


# Here are some examples:

print ancestors(ada_family, 'Augusta Ada King')
#>>> ['Anne Isabella Milbanke', 'George Gordon Byron',
#    'Catherine Gordon','Captain John Byron']

print ancestors(ada_family, 'Judith Blunt-Lytton')
#>>> ['Anne Isabella Blunt', 'Wilfrid Scawen Blunt', 'Augusta Ada King',
#    'William King-Noel', 'Anne Isabella Milbanke', 'George Gordon Byron',
#    'Catherine Gordon', 'Captain John Byron']

print ancestors(ada_family, 'Dave')
#>>> []