Python - Storing Data Using Other Collection Types(list, set, in)

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) 1.を解いてみる。

11.8(Exercises) 1.

コード(BBEdit)

sample1.py

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

import random

def findDups(nums):
    s1 = set()
    s2 = set()
    for num in nums:
        if num in s1:
            s2.add(num)
        else:
            s1.add(num)
    return s2

nums = [random.randrange(10) for x in range(20)]
print(nums)
print(findDups(nums))

入出力結果(Terminal, IPython)

$ ./sample1.py
[8, 8, 0, 3, 8, 3, 5, 9, 5, 9, 9, 3, 1, 9, 3, 2, 9, 9, 9, 3]
{8, 9, 3, 5}
$ ./sample1.py
[2, 3, 7, 6, 6, 9, 2, 0, 8, 3, 9, 7, 5, 4, 5, 0, 0, 3, 9, 3]
{0, 2, 3, 5, 6, 7, 9}
$