Python.use(better) #課題：組み込み型 list《test case》
‖記事一覧‖ Python.use(better)《Python3.1》
《余録》課題：組み込み型 list《test case》
《著》森こねこ、小粒ちゃん＋∞《監修》小泉ひよ子とタマゴ倶楽部
第０版♪2001/03/02 ● 第１版♪2003/05/25 ● 第２版♪2004/06/01 ● 第３版♪2009/02/28
組み込み型と同等の機能を実現する課題を通して「OOP」の理解を深めます。
※ Python1.5 で作成した例題を、Python3.1 で再構成しました。
課題：テストケース
Python 3.1 (r31:73578, Jun 27 2009, 21:49:46) [GCC 4.0.1 (Apple Inc. build 5493)] on darwin Type "copyright", "credits" or "license()" for more information. >>> ================================ RESTART ================================ >>> myList.py #1.0a*0 ======================== Mon Dec 7 03:57:41 2009 ======================== ********************************************************************** File "__main__", line 6, in __main__ Failed example: None Expected: version: #1.0.51 Got nothing ********************************************************************** 1 items had failures: 1 of 2 in __main__ ***Test Failed*** 1 failures. >>> do_all() >>> # ======================================== step00 >>> # >>> s = myList(); s <__main__.myList object at 0x12e9530> >>> # ======================================== step01 >>> # >>> s = myList(); s >>> # ======================================== step02 >>> # >>> s = myList(); s >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ======================================== step03 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ======================================== step04 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ======================================== step05 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ======================================== step06 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ======================================== step07 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ======================================== step08 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ======================================== step09 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ======================================== step10 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ======================================== step11 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ---------------------------------------- insert >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(0,"_"); s, len(s) (['_', 'A', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(1,"_"); s, len(s) (['A', '_', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(2,"_"); s, len(s) (['A', 'B', '_', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(3,"_"); s, len(s) (['A', 'B', 'C', '_'], 4) >>> # ======================================== step12 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ---------------------------------------- insert >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(0,"_"); s, len(s) (['_', 'A', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(1,"_"); s, len(s) (['A', '_', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(2,"_"); s, len(s) (['A', 'B', '_', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(3,"_"); s, len(s) (['A', 'B', 'C', '_'], 4) >>> # ---------------------------------------- extend >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend(''); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend('D'); s, len(s) (['A', 'B', 'C', 'D'], 4) >>> s.extend('EF'); s, len(s) (['A', 'B', 'C', 'D', 'E', 'F'], 6) >>> # ======================================== step13 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ---------------------------------------- insert >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(0,"_"); s, len(s) (['_', 'A', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(1,"_"); s, len(s) (['A', '_', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(2,"_"); s, len(s) (['A', 'B', '_', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(3,"_"); s, len(s) (['A', 'B', 'C', '_'], 4) >>> # ---------------------------------------- extend >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend(''); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend('D'); s, len(s) (['A', 'B', 'C', 'D'], 4) >>> s.extend('EF'); s, len(s) (['A', 'B', 'C', 'D', 'E', 'F'], 6) >>> # ---------------------------------------- __delitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[0]; s, len(s) (['B', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[1]; s, len(s) (['A', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[2]; s, len(s) (['A', 'B'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[3]; s, len(s) IndexError: myList assignment index out of range >>> # ======================================== step14 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ---------------------------------------- insert >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(0,"_"); s, len(s) (['_', 'A', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(1,"_"); s, len(s) (['A', '_', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(2,"_"); s, len(s) (['A', 'B', '_', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(3,"_"); s, len(s) (['A', 'B', 'C', '_'], 4) >>> # ---------------------------------------- extend >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend(''); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend('D'); s, len(s) (['A', 'B', 'C', 'D'], 4) >>> s.extend('EF'); s, len(s) (['A', 'B', 'C', 'D', 'E', 'F'], 6) >>> # ---------------------------------------- __delitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[0]; s, len(s) (['B', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[1]; s, len(s) (['A', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[2]; s, len(s) (['A', 'B'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[3]; s, len(s) IndexError: myList assignment index out of range >>> # ---------------------------------------- remove >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('A'); s ['B', 'C'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('B'); s ['A', 'C'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('C'); s ['A', 'B'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('@'); s ValueError: ValueError: myList.remove(x): x not in myList >>> # ======================================== step15 >>> # >>> # ---------------------------------------- __init__ >>> s = myList(); s >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> # ---------------------------------------- append >>> s = myList(); s >>> s.append('A'); s ['A'] >>> s.append('B'); s ['A', 'B'] >>> s.append('C'); s ['A', 'B', 'C'] >>> # ---------------------------------------- __len__ >>> s = myList(); s, len(s) (, 0) >>> s.append('A'); s, len(s) (['A'], 1) >>> s.append('B'); s, len(s) (['A', 'B'], 2) >>> s.append('C'); s, len(s) (['A', 'B', 'C'], 3) >>> # ---------------------------------------- __contains__ >>> s = myList(); s, len(s) (, 0) >>> 'A' in s False >>> '@' in s False >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> 'A' in s True >>> '@' in s False >>> # ---------------------------------------- count >>> s = myList("as happy as happy can be"); s ['a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'a', 's', ' ', 'h', 'a', 'p', 'p', 'y', ' ', 'c', 'a', 'n', ' ', 'b', 'e'] >>> s.count('p') 4 >>> s.count('y') 2 >>> s.count('t') 0 >>> s.count('h') 2 >>> s.count('o') 0 >>> s.count('n') 1 >>> # ---------------------------------------- index >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.index('A') 0 >>> s.index('B') 1 >>> s.index('C') 2 >>> s.index('@') ValueError: myList.index(x): x not in myList >>> # ---------------------------------------- __getitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] 'A' >>> s[1] 'B' >>> s[2] 'C' >>> s[3] IndexError: myList index out of range >>> # ---------------------------------------- __setitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s[0] = 'X'; s, len(s) (['X', 'B', 'C'], 3) >>> s[1] = 'Y'; s, len(s) (['X', 'Y', 'C'], 3) >>> s[2] = 'Z'; s, len(s) (['X', 'Y', 'Z'], 3) >>> # ---------------------------------------- insert >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(0,"_"); s, len(s) (['_', 'A', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(1,"_"); s, len(s) (['A', '_', 'B', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(2,"_"); s, len(s) (['A', 'B', '_', 'C'], 4) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.insert(3,"_"); s, len(s) (['A', 'B', 'C', '_'], 4) >>> # ---------------------------------------- extend >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend(''); s, len(s) (['A', 'B', 'C'], 3) >>> s.extend('D'); s, len(s) (['A', 'B', 'C', 'D'], 4) >>> s.extend('EF'); s, len(s) (['A', 'B', 'C', 'D', 'E', 'F'], 6) >>> # ---------------------------------------- __delitem__ >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[0]; s, len(s) (['B', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[1]; s, len(s) (['A', 'C'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[2]; s, len(s) (['A', 'B'], 2) >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> del s[3]; s, len(s) IndexError: myList assignment index out of range >>> # ---------------------------------------- remove >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('A'); s ['B', 'C'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('B'); s ['A', 'C'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('C'); s ['A', 'B'] >>> s = myList("ABC"); s, len(s) (['A', 'B', 'C'], 3) >>> s.remove('@'); s ValueError: ValueError: myList.remove(x): x not in myList >>> # ---------------------------------------- pop >>> s = myList("ABC"); s ['A', 'B', 'C'] >>> s.pop(), s ('C', ['A', 'B']) >>> s.pop(), s ('B', ['A']) >>> s.pop(), s ('A', ) >>> s.pop(), s IndexError: IndexError: pop from empty myList >>>
Python.use(better) #Vector: step12x -- raise(TypeError(s))
‖記事一覧‖ Python.use(better)《Python3.1》
raise(TypeError(s))
《著》森こねこ、小粒ちゃん＋∞《監修》小泉ひよ子とタマゴ倶楽部
第０版♪2001/03/02 ● 第１版♪2003/05/25 ● 第２版♪2004/06/01 ● 第３版♪2009/02/28
課題を作成する過程を通して「数値演算」の理解を深めます。
※ Python1.5 で作成した例題を、Python3.1 で再構成しました。
事例：コードの解説
class Vector(object): ... def __add__(v1, v2): s = [e1+e2 for e1,e2 in zip(v1, v2)] return Vector(*s) def __radd__(self, other): #@: return self+other
■ #1: メソッド：__radd__
def __radd__(self, other): #@:
return self+other
メソッド __radd__ は、２項演算子 + に呼応して、２つのベクトルの「和」を表わすインスタンスを生成します。２項演算子 * の左項と右項に着目すると、
- 左項が Vector であるなら、左項と右項はそのままで、__add__ が呼び出されます。
- 左項が Vector でないなら、左項と右項を入れ換えて、__radd__ が呼び出され、
- 引数 self を介してベクトルを、引数 other を介して整数を参照できます。
すると、メソッド __radd__ は、２項演算子 + を再利用するだけで、簡潔に表現できます。
- ２項演算子 + は、メソッド __add__ に帰結します。
《Note》self：引数 self を介して参照されるオブジェクトは、実行時に確定します。すると、そのオブジェクトが何であっても、適切なメソッドが呼び出されます。ここでは、クラス Vector のメソッド本体に記述したコードの断片が実行されます。
事例：モジュールを起動する
■ 全項目を確認する
全ステップの「項目」を確認するには、関数 do を利用します。
$ python -i vector.py >>> do() 0: step00 -- class Vector(object): 1: step01 -- def __init__(self, *args): 2: step02x -- def __add__(v1, v2): 3: step03 -- return Vector(*s) 4: step04 -- def __sub__(v1, v2): 5: step05 -- def __neg__(self): 6: step06 -- def __mul__(v1, v2): 7: step07x -- sum(e1*e2 ...) 8: step08x -- if hasattr(v2, "elements"): 9: step09 -- def __rmul__(self, other): 10: step10 -- def __iter__(self): 11: step11x -- def __radd__(self, other): 12: step12x -- raise(TypeError(s)) 13: step13 -- raise(TypeError(s)) 14: step14 -- def _typeError(self, v1, v2, op): >>>
■ 各項目を実行する
各ステップの「動作」を確認するには、関数 do に実引数を指定します。
>>> do(11) >>> # -------------------------------------------------- step11x >>> v = Vector(); v () >>> v1 = Vector(3,4); v1 (3, 4) >>> v2 = Vector(5,-2); v2 (5, -2) >>> v1+v2 (8, 2) >>> v1-v2 (-2, 6) >>> v2-v1 (2, -6) >>> -v1 (-3, -4) >>> -v2 (-5, 2) >>> v1*v2 7 >>> v2*v1 7 >>> v1*3 (9, 12) >>> v2*(-2) (-10, 4) >>> 3*v1 (9, 12) >>> (-2)*v2 (-10, 4) >>> 2+v1 TypeError: zip argument #2 must support iteration >>> v2+5 TypeError: zip argument #2 must support iteration >>> 2-v1 TypeError: unsupported operand type(s) for -: 'int' and 'Vector' >>> v2-5 TypeError: zip argument #2 must support iteration >>> >>> do(12) >>> # -------------------------------------------------- step12x >>> v = Vector(); v () >>> v1 = Vector(3,4); v1 (3, 4) >>> v2 = Vector(5,-2); v2 (5, -2) >>> v1+v2 (8, 2) >>> v1-v2 (-2, 6) >>> v2-v1 (2, -6) >>> -v1 (-3, -4) >>> -v2 (-5, 2) >>> v1*v2 7 >>> v2*v1 7 >>> v1*3 (9, 12) >>> v2*(-2) (-10, 4) >>> 3*v1 (9, 12) >>> (-2)*v2 (-10, 4) >>> 2+v1 TypeError: unsupported operand type(s) for +: 'Vector' and 'int' >>> v2+5 TypeError: unsupported operand type(s) for +: 'Vector' and 'int' >>> 2-v1 TypeError: unsupported operand type(s) for -: 'int' and 'Vector' >>> v2-5 TypeError: unsupported operand type(s) for +: 'Vector' and 'int'
■ 何が問題か
ただし、
- 任意の整数とベクトルとを加減しようとすると、例外 TypeError を生成します。
- ベクトルと任意の整数とを加減しようとすると、例外 TypeError を生成します。
例外 TypeError に伴うエラーメッセージからは、利用者にとって意味のある情報が得られるとはかぎりません。その中には、メソッドの実現方法に依存する情報などが含まれます。
《余録》テストケース
def ex_vector8(local): #@:
ex_vector7(local)
source = '''
2+v1
v2+5
2-v1
v2-5
'''.split("\n")
do_it(source, local)
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