《Learn python the hard way》Exercise 48: Advanced User Input

这几天有点时间，想学点Python基础，今天看到了《learn python the hard way》的 Ex48，这篇文章主要记录一些工具的安装，以及scan 函数的实现。

首先与Ex48相关的章节有前面的Ex46, Ex47，故我们需要先安装一些工具，主要是一些包管理和测试框架的软件：

Install the following Python packages:

pip from http://pypi.python.org/pypi/pip
distribute from http://pypi.python.org/pypi/distribute
nose from http://pypi.python.org/pypi/nose/
virtualenv from http://pypi.python.org/pypi/virtualenv

实际上对于Linux用户来说安装比较简单，首先安装 sudo apt-get install python-pip，接下去的3个都可以使用pip 来安装，即

pip install distribute/nose/virtualenv

模仿Ex46 的描述，新建工程目录为ex47，进而建立以下目录和文件：

setup.py 如下，一些参数可以设置成自己想要的，如NAME 更改为需要测试的多个模块名：

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try:
     from setuptools import setup
except ImportError:
     from distutils.core import setup

config = {
     'description': 'My Project',
     'author': 'My Name',
     'url': 'URL to get it at.',
     'download_url': 'Where to download it.',
     'author_email': 'My email.',
     'version': '0.1',
     'install_requires': [ 'nose'],
     'packages': [ 'NAME'],
     'scripts': [],
     'name': 'projectname'
}

setup(**config)

在ex47 和 tests 目录下各touch新建一个__init__.py 文件。

测试文件 tests/lexicon_tests.py 摘自网站：

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from nose.tools import *
from ex47 import lexicon

def test_directions():
    assert_equal(lexicon.scan( "north"), [( 'direction', 'north')])
    result = lexicon.scan( "north south east")
    assert_equal(result, [( 'direction', 'north'),
                          ( 'direction', 'south'),
                          ( 'direction', 'east')])

def test_verbs():
    assert_equal(lexicon.scan( "go"), [( 'verb', 'go')])
    result = lexicon.scan( "go kill eat")
    assert_equal(result, [( 'verb', 'go'),
                          ( 'verb', 'kill'),
                          ( 'verb', 'eat')])

def test_stops():
    assert_equal(lexicon.scan( "the"), [( 'stop', 'the')])
    result = lexicon.scan( "the in of")
    assert_equal(result, [( 'stop', 'the'),
                          ( 'stop', 'in'),
                          ( 'stop', 'of')])

def test_nouns():
    assert_equal(lexicon.scan( "bear"), [( 'noun', 'bear')])
    result = lexicon.scan( "bear princess")
    assert_equal(result, [( 'noun', 'bear'),
                          ( 'noun', 'princess')])

def test_numbers():
    assert_equal(lexicon.scan( "1234"), [( 'number', 1234)])
    result = lexicon.scan( "3 91234")
    assert_equal(result, [( 'number', 3),
                          ( 'number', 91234)])

def test_errors():
    assert_equal(lexicon.scan( "ASDFADFASDF"), [( 'error', 'ASDFADFASDF')])
    result = lexicon.scan( "bear IAS princess")
    assert_equal(result, [( 'noun', 'bear'),
                          ( 'error', 'IAS'),
                          ( 'noun', 'princess')])

上面程序中 from ex47 import lexicon 表示从ex47 中导入lexicon 模块，即现在我们要在ex47 目录下写一个lexicon.py 文件，文件主要是scan 函数的实现，根据网站的提示，自己实现如下：

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#!/usr/bin/env python
#coding=utf-8

import re

def convert_number(s):
     try:
         return int(s)
     except ValueError:
         return None

def scan(input_str):

    words = input_str. split( ' ')

    pattern = re. compile(r 'd+')


    direction_list = [ 'north', 'south', 'west', 'east', 'down', 'up', 'left', 'right', 'back']
    verb_list = [ 'go', 'kill', 'stop', 'eat']
    stop_list = [ 'the', 'in', 'of', 'from', 'at', 'it']
    noun_list = [ 'door', 'bear', 'princess', 'cabinet']
    sentence_list = []

     for word in words:

         bool = pattern.match(word)
         if bool:
            sentence = ( 'number', convert_number(word))
            sentence_list. append(sentence)

         elif word in direction_list:
            sentence = ( 'direction', word)
            sentence_list. append(sentence)


         elif word in verb_list:
            sentence = ( 'verb', word)
            sentence_list. append(sentence)

         elif word in stop_list:
            sentence = ( 'stop', word)
            sentence_list. append(sentence)

         elif word in noun_list:
            sentence = ( 'noun', word)
            sentence_list. append(sentence)

         else:
            sentence = ( 'error', word)
            sentence_list. append(sentence)

     return sentence_list

程序中使用正则表达式来匹配数字字符串，请google re 模块之。

执行测试命令，即使用lexicon_tests.py 去测试lexicon.py 里面的函数，输出如下：

simba@ubuntu:~/Documents/code/python/projects/ex47$ nosetests
.........
----------------------------------------------------------------------
Ran 9 tests in 0.081s

OK

为什么是9个tests 呢，上面只有6个，实际上我在ex47 下还有个game.py，而针对这个模块的测试文件game_tests.py也存在tests 目录下，且里面有3个test, 故这个项目总的测试个数是9个，需要针对一个模块写一个测试文件。

参考：http://learnpythonthehardway.org/book/ex48.html