Python - Statements and Syntax(while and for loop(break, else))

Learning Python
(Oreilly & Associates Inc)
Mark Lutz (著)
(邦訳版)

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)

Learning Python (Mark Lutz (著)、Oreilly & Associates Inc)のPART Ⅲ.(Statements and Syntax)、Chapter 13.(while and for loop)、Test Your Knowledge: Quiz 3.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 (原書(最新版))
• Programming Python
• Python Pocket Reference (Pocket Reference (O'Reilly))

Test Your Knowledge: Quiz 3.

コード(BBEdit)

sample3.py

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

# while loop、for loopがbreak文で終わらなかったときに、else clauseは実行される

def isPrime1(n):
    i = 2
    while i <= n / 2:
        if n % i == 0:
            print('{0}: not prime'.format(n))
            break
        i += 1
    else:
        print('{0}: prime'.format(n))

def isPrime2(n):
    print(n, end=': ')
    for i in range(2, n // 2 + 1):
        if n % i == 0:
            print('not prime')
            break
    else:
        print('prime')

for n in range(2, 21):
    isPrime1(n)
    isPrime2(n)       

入出力結果(Terminal, IPython)

$ ./sample3.py
2: prime
2: prime
3: prime
3: prime
4: not prime
4: not prime
5: prime
5: prime
6: not prime
6: not prime
7: prime
7: prime
8: not prime
8: not prime
9: not prime
9: not prime
10: not prime
10: not prime
11: prime
11: prime
12: not prime
12: not prime
13: prime
13: prime
14: not prime
14: not prime
15: not prime
15: not prime
16: not prime
16: not prime
17: prime
17: prime
18: not prime
18: not prime
19: prime
19: prime
20: not prime
20: not prime
$