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

2022-10-07 07:25:53

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',
)])

    result = lexicon.scan(
"3 91234")

    assert_equal(result, [(
'number',
),

                          (
'number',
)])

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

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

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