Python - クラスとオブジェクト指向プログラミング (Setクラス(listの継承を使わずに自作))

初めてのPython 第3版
Mark Lutz (著)
夏目 大 (翻訳)

開発環境

• OS X Lion - Apple(OS)
• BBEdit - Bare Bones Software, Inc., Emacs(Text Editor)
• プログラミング言語: Python

『初めてのPython 第3版』(Mark Lutz 著、夏目 大 訳、オライリー・ジャパン、2009年、ISBN978-4-87311-393-7)のIV部(クラスとオブジェクト指向プログラミング)、まとめ演習5.(Setクラス)を解いてみる。

その他参考書籍

• Pythonチュートリアル 第2版
• Python クックブック 第2版

まとめ演習5.(Setクラス)

sample.py

#!/usr/bin/env python3.3
#-*- coding: utf-8 -*-

class Set:
    def __init__(self, value = []):
        self.data = []
        self.concat(value)
    
    def intersect(self, other):
        res = []
        for x in self.data:
            if x in other:
                res.append(x)
        return Set(res)
    
    def union(self, other):
        res = self.data[:]
        for x in other:
            if not x in res:
                res.append(x)
        return Set(res)
    
    def concat(self, value):
        for x in value:
            if not x in self.data:
                self.data.append(x)
    
    def __add__(self, other):
        self.concat(other)
        return Set(self.data)
    def __len__(self): return len(self.data)
    def __getitem__(self, key): return self.data[key]
    def __and__(self, other): return self.intersect(other)
    def __or__(self, other): return self.union(other)
    def __repr__(self): return 'Set: {0}'.format(self.data)
    def __getattr__(self, attrname): # 処理を委託(デリゲーション)
        return getattr(self.data, attrname)

class SetSub(Set):
    def intersect(self, *others):
        res = []
        for x in self.data:
            for other in others:
                if not x in other:
                    break
            else:
                res.append(x)
        return SetSub(res)
    def union(self, *others):
        res = self.data[:]
        for other in others:
            for x in other:
                if not x in res:
                    res.append(x)
        return SetSub(res)

if __name__ == '__main__':
    s1 = Set([1,2,3,4,5])
    s2 = Set([2,4,6,8,10])
    print("s1 {0}, s2 {1}".format(s1, s2))
    print("& {0}".format(s1 & s2))
    print("| {0}".format(s1 | s2))
    s1 = Set("abcde")
    print("s1 {0}".format(s1))
    print("s1[0] {0}".format(s1[1])) # __getitem__が呼び出される
    for c in s1:
        print(c)
    s2 = "defghijklmn"
    print("s2 {0}".format(s2))
    try:
        print("& {0}".format(s1 & s2))
    except Exception as err:
        print(type(err), err)
    try:
        print("| {0}".format(s1 | s2))
    except Exception as err:
        print(type(err), err)
    s1 = SetSub([1,2,3,4,5])
    s2 = SetSub([6,7,8,9,10])
    even = SetSub([2,4,6,8,10])
    odd = SetSub([1,3,5,7,9])
    s = SetSub([1, 2, 8, 10, 12, 14, 16])
    print(s1.intersect(even, s))
    print(s1.union(s2, even, odd, s))
    s1 = Set([1,2,3,4,5])
    s2 = Set([2,4,6,8,10])
    print(s1 + s2)
    s1.clear()
    print(s1)
    print(s2.index(4))
    print(s2.pop())
    print(s2)

入出力結果(Terminal)

$ ./sample.py
s1 Set: [1, 2, 3, 4, 5], s2 Set: [2, 4, 6, 8, 10]
& Set: [2, 4]
| Set: [1, 2, 3, 4, 5, 6, 8, 10]
s1 Set: ['a', 'b', 'c', 'd', 'e']
s1[0] b
a
b
c
d
e
s2 defghijklmn
& Set: ['d', 'e']
| Set: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n']
Set: [2]
Set: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16]
Set: [1, 2, 3, 4, 5, 6, 8, 10]
Set: []
1
10
Set: [2, 4, 6, 8]
$