《Learn python the hard way》Exercise 48: Advanced User Input
《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ex48，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 更改为需要测试的模块名：
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ex48 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：
from nose.tools import *
from ex48 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 ex48 import lexicon 表示从ex48 中 导入lexicon 模块，即现在我们要在ex48 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：
#!/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/ex48$ nosetests ......... Ran 6 tests in 0.007s OK
参考 ：http://learnpythonthehardway.org/book/ex48.html
后记：
如果在使用pip or easy_install 时提示url不正确，可以临时修改或者修改配置文件中的index-url为国内镜像点。
下载完成，编译安装过程中如果提示不存在python.h，可以 sudo apt-get install python-dev or yum install python-devel