Python - Storing Data Using Other Collection Types(dictionary, union, update method(in-place))

Practical Programming
An Introduction to Computer Science
Using Python 3
(Pragmatic Programmers)
(Pragmatic Bookshelf)
Paul Gries (著) Jennifer Campbell (著)
Jason Montojo (著) Lynn Beighley (編集)

開発環境

• OS X Mavericks - Apple(OS)
• Emacs (CUI)、BBEdit - Bare Bones Software, Inc. (GUI) (Text Editor)
• Python 3.4 (プログラミング言語)

Practical Programming: An Introduction to Computer Science Using Python 3 (Pragmatic Programmers) (Paul Gries (著)、Jennifer Campbell (著)、Jason Montojo (著)、Lynn Beighley (編集)、Pragmatic Bookshelf)のChapter 11(Storing Data Using Other Collection Types)、11.8(Exercises) 9.を解いてみる。

11.8(Exercises) 9.

コード(BBEdit)

sample9.py

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

def dbHeadings(db):
    result = set()
    
    for value in db.values():
        result.update(value.keys())
    
    return result
        
if __name__ == '__main__':
    db = {
        'jgoodall'  : {'surname'  : 'Goodall',
                       'forename' : 'Jane',
                       'born'     : 1934,
                       'died'     : None,
                       'notes'    : 'primate researcher',
                       'author'   : ['In the Shadow of Man',
                                     'The Chimpanzees of Gombe']},
        'rfranklin' : {'surname'  : 'Franklin',
                       'forename' : 'Rosalind',
                       'born'     : 1920,
                       'died'     : 1957,
                       'notes'    : 'contributed to discovery of DNA'},
        'rcarson'  : {'surname'  : 'Carson',
                      'forename' : 'Rachel',
                      'born'     : 1907,
                      'died'     : 1964,
                      'notes'    : 'raised awareness of effects of DDT',
                      'author'   : ['Silent Spring']
                  }
    }
    print(dbHeadings(db))

入出力結果(Terminal, IPython)

$ ./sample9.py
{'born', 'author', 'forename', 'notes', 'surname', 'died'
$