9-2

#! /usr/bin/env python3.2
# -*- coding: utf-8 -*-

# main.py
""" Task: Exercise 9.2
    Dictionaries have a method called get that takes a key and a default value.
    If the key appears in the dictionary, get returns the corresponding value;
    otherwise it returns the default value. For example:

    >>> h = histogram('a')
    >>> print h
    {'a': 1}
    >>> h.get('a', 0)
    1
    >>> h.get('b', 0)
    0

    Use get to write histogram more concisely. You should be able to eliminate
    the if statement.

    def histogram(s):
        d = dict()
        for c in s:
            if c not in d:
                d[c] = 1
            else:
                d[c] = d[c] + 1
        return d
"""

''' Functions '''
def histogram(s):
    d = dict()
    for c in s:
        d[c] = d.get(c, 0) + 1  # if c does not exist in d, it will be inserted
                                # with the value of 0+1 = 1
    return d

''' Test '''
h = histogram('brontosaurus')
print(h)