Python -textual(string, find method, substring, index0

Head First Programming
A learner's guide to programming
using the Python language
( O'Reilly Media; )
David Griffiths (著) Paul Barry (著)

開発環境

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

Head First Programming A learner's guide to programming using the Python language (David Griffiths(著)、Paul Barry(著)、 O'Reilly Media; )のChapter 2(textual data: Every string has its place)、Exercise(p.57)を解いてみる。

Exercise(p.57)

コード(BBEdit)

sample57.py

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

import urllib.request

page = urllib.request.urlopen(
    'http://beans-r-us.appspot.com/prices-loyalty.html')
text = page.read().decode('utf8')

i = text.find('>$')
if i != -1:
    price = text[i+2:i+6]
    print(price)

入出力結果(Terminal)

$ ./sample57.py
4.61
$