lab05.py

def tree(root, branches=[]):
    return lambda dispatch: root if dispatch == 'root' else list(branches)
    
def root(tree):
    return tree('root')
    
def branches(tree):
    return tree('branches')
    
t = tree(1,
         [tree(2),
          tree(3,
               [tree(4),
                tree(5)]),
          tree(6,
               [tree(7)])])
               

def print_tree(t, indent=0):
    print('  ' * indent + str(root(t)))
    for branch in branches(t):
        print_tree(branch, indent + 1)

""" Q1
Define the function countdown_tree so that it returns 
the specific tree below.Make sure to use the tree constructor 
from the Data Abstraction!"""

def countdown_tree():
    """Return a tree that has the following structure.

    >>> print_tree(countdown_tree())
    10
      9
        8
      7
        6
          5
    """
    "*** YOUR CODE HERE ***"
    return tree(10,[tree(9,[tree(8)]),tree(7,[tree(6,[tree(5)])])])
    
print_tree(countdown_tree())


""" Q2
Define the function size_of_tree, which takes in a tree 
as an argument and returns the number of entries in the tree."""

def size_of_tree(t):
    """Return the number of entries in the tree.

    >>> print_tree(numbers)
    1
      2
      3
        4
        5
      6
        7
    >>> size_of_tree(numbers)
    7
    """
    "*** YOUR CODE HERE ***"
    return 1 + sum([size_of_tree(t) for t in branches(t)])
    # alt solution
    """ 
    return len(t)
    if len(branches(t))==0:
        return 1
    else:
        size=1
        for branch in branches(t):
            size += size_of_tree(branch)
        return size """

    
def counter(message):
    """ Returns a dictionary of each word in message mapped
    to the number of times it appears in the input string.

    >>> x = counter('to be or not to be')
    >>> x['to']
    2
    >>> x['be']
    2
    >>> x['not']
    1
    >>> y = counter('run forrest run')
    >>> y['run']
    2
    >>> y['forrest']
    1
    """
    word_list = message.split()
    "*** YOUR CODE HERE ***"
    words = {}
    for i in word_list:
        if not i in words:
            words[i] = 1
        else:
            words[i] += 1
    return words

# Q3


def counter(message):
    """ Returns a dictionary of each word in message mapped
    to the number of times it appears in the input string.

    >>> x = counter('to be or not to be')
    >>> x['to']
    2
    >>> x['be']
    2
    >>> x['not']
    1
    >>> y = counter('run forrest run')
    >>> y['run']
    2
    >>> y['forrest']
    1
    """
    word_list = message.split()
    "*** YOUR CODE HERE ***"
    words = {}
    for i in word_list:
        if i not in words:
            words[i] = 1 # add all words as keys in a dict and count values
        else:
            words[i] += 1 # keep count if key appears in list
    return words
    
x = counter('to be or not to be')

resp = x['be']