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Django入门进阶

作者：Adam at 2016-11-18 00:58:51

我们前面讲了快速熟悉Django架构网站的方式，接下来我们来深入了解一下Django框架。它不仅提供了建站的方法，也提供了一整套的从开发简单的网站到一个完整维护迭代的开发模式，下面几个方面非常重要。

学会调试

  • 单步调试
    直接在代码中插入下面这一行：

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    #polls/views.py
    from django.shortcuts import get_object_or_404, render
    from .models import Question
    import pdb; pdb.set_trace() #这一行

    运行程序，就可以在服务器端命令行中一步步的跟踪执行结果。

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    [26/Nov/2016 14:17:49] "GET /polls/ HTTP/1.1" 200 72
    Performing system checks...
    > /myFirstDjango/mysite/polls/views.py(6)<module>()
    -> def index(request):
    (Pdb) l ＃这是调试命令：展示当前运行代码
      1  	from django.shortcuts import get_object_or_404, render
      2
      3  	from .models import Question
      4  	import pdb; pdb.set_trace()
      5  	# Create your views here.
      6  ->	def index(request):
      7  	    latest_question_list = Question.objects.order_by('-pub_date')[:5]
      8  	    context = {
      9  	        'latest_question_list': latest_question_list,
     10  	    }
     11  	    return render(request, 'polls/index.html', context)
    (Pdb) n ＃这是调试命令: 下一步
    > /Users/gzadamlv/myFirstDjango/mysite/polls/views.py(13)<module>()
    -> def detail(request, question_id):
    (Pdb) h ＃这是调试命令：获取帮助，查看所有可用命令
    Documented commands (type help <topic>):
    ========================================
    EOF    bt         cont      enable  jump  pp       run      unt
    a      c          continue  exit    l     q        s        until
    alias  cl         d         h       list  quit     step     up
    args   clear      debug     help    n     r        tbreak   w
    b      commands   disable   ignore  next  restart  u        whatis
    break  condition  down      j       p     return   unalias  where
    ...

  • Shell 调试方式
    用下面的命令进入命令行

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    (myFirstDjango)➜  mysite git:(master) ✗ python manage.py shell
    Python 2.7.10 (default, Oct 23 2015, 19:19:21)
    [GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
    Type "help", "copyright", "credits" or "license" for more information.
    (InteractiveConsole)
    >>>

通过在命令行引入程序中使用的模块、函数来跟踪返回结果。

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>>> django.setup()
>>> import mysite
>>> from django.shortcuts import get_object_or_404, render
>>> from polls.models import Question
>>> latest_question_list = Question.objects.order_by('-pub_date')[:5]
>>> print(latest_question_list)
<QuerySet [<Question: 你会学习python吗？>]>

学会测试

修改models.py

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from django.utils import timezone
import datetime

给class Question增加一个方法

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def was_published_recently(self):
    return self.pub_date >= timezone.now() - datetime.timedelta(days=1)

添加测试文件：polls/tests.py

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import datetime
from django.utils import timezone
from django.test import TestCase
from .models import Question
class QuestionMethodTests(TestCase):
    def test_was_published_recently_with_future_question(self):
        """
        was_published_recently() should return False for questions
        whose pub_date is in the future.
        """
        time = timezone.now() + datetime.timedelta(days=30)
        future_question = Question(pub_date=time)
        self.assertIs(future_question.was_published_recently(), False)

运行测试

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(myFirstDjango)➜  mysite git:(master) ✗ python manage.py test polls
Creating test database for alias 'default'...
F
======================================================================
FAIL: test_was_published_recently_with_future_question (polls.tests.QuestionMethodTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/gzadamlv/myFirstDjango/mysite/polls/tests.py", line 14, in test_was_published_recently_with_future_question
    self.assertIs(future_question.was_published_recently(), False)
AssertionError: True is not False
----------------------------------------------------------------------
Ran 1 test in 0.002s
FAILED (failures=1)
Destroying test database for alias 'default'...

修改was_published_recently方法

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#return self.pub_date >= timezone.now() - datetime.timedelta(days=1)
now = timezone.now()
return now - datetime.timedelta(days=1) <= self.pub_date <= now

再运行测试

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(myFirstDjango)➜  mysite git:(master) ✗ python manage.py test polls
Creating test database for alias 'default'...
.
----------------------------------------------------------------------
Ran 1 test in 0.001s
OK
Destroying test database for alias 'default'...

学会写文档

安装： pip install Sphinx
运行 sphinx-quickstart 命令(下面几项要选yes)

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Please indicate if you want to use one of the following Sphinx extensions:
> autodoc: automatically insert docstrings from modules (y/n) [n]: y
> doctest: automatically test code snippets in doctest blocks (y/n) [n]: y
> intersphinx: link between Sphinx documentation of different projects (y/n) [n]: y
> todo: write "todo" entries that can be shown or hidden on build (y/n) [n]: y
> coverage: checks for documentation coverage (y/n) [n]: y

生成文档： make html
打开网页：_build/html/index.html

默认模版不太好看，我们新加一个主题：pip install sphinx_rtd_theme
在conf.py最后增加：

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import sphinx_rtd_theme
html_theme = 'sphinx_rtd_theme'

再make html，初始化文档生成成功：
2016-11-30-截图

但是我们会发现并没有看到程序中的文档，别着急，还差两步。

先用sphinx-apidoc把app目录中python程序的文档内容提取出来，保存到api这个目录。

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sphinx-apidoc -o api ./app -f

最后，我们需要编辑index.rst这个文件：

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Contents:
.. toctree::
   :maxdepth: 2
   api/polls.rst  #增加这行

再次make html，大功告成～

2016-11-30-截图

这是提取出来的具体文档：

2016-11-30-截图

另外：如果make html出现下面错误

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sphinx autodoc ImportError: No module named

可以试试这个：

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export PYTHONPATH=$(pwd)

别小看上面这三步，其实还有很多细节没能和大家演示，师傅领进门，修行靠个人哦～