So, I started learning to code in Python and later Django. The first times it was hard looking at tracebacks and actually figure out what I did wrong and where the syntax error was. Some time has passed now and some way along the way, I guess I got a routine in debugging my Django code. As this was done early in my coding experience, I sat down and wondered if how I was doing this was ineffective and could be done faster. I usually manage to find and correct the bugs in my code, but I wonder if I should be doing it faster?

我通常只使用Django启用时提供的调试信息。当事情确实像我想象的那样结束时,我用一个语法错误破坏了代码流,并查看流中那个点的变量,以找出代码在哪里做了与我想要的不同的事情。

但这种情况还能改善吗?是否有一些更好的工具或方法来调试Django代码?


当前回答

我使用PyCharm(与eclipse相同的pydev引擎)。真的帮助我能够直观地逐级检查我的代码,并看到发生了什么。

其他回答

我刚找到wdb (http://www.rkblog.rk.edu.pl/w/p/debugging-python-code-browser-wdb-debugger/?goback=%2Egde_25827_member_255996401)。它有一个非常漂亮的用户界面/ GUI,所有的铃铛和口哨。作者这样说wdb -

“像PyCharm这样的ide有自己的调试器。它们提供了相似或相同的功能……然而,要使用它们,你必须使用那些特定的ide(其中一些是非免费的,或者可能不适用于所有平台)。根据你的需要选择合适的工具。”

我想我应该把它传下去。

这也是一篇关于python调试器的非常有用的文章: https://zapier.com/engineering/debugging-python-boss/

最后,如果你想在Django中看到一个漂亮的调用堆栈的图形打印输出,checkout: https://github.com/joerick/pyinstrument。只需将pyinstrument.middleware.ProfilerMiddleware添加到MIDDLEWARE_CLASSES中,然后将?profile添加到请求URL的末尾以激活剖析器。

也可以从命令行或导入作为模块运行pyinstrument。

我强烈推荐epdb(扩展Python调试器)。

https://bitbucket.org/dugan/epdb

我喜欢用epdb来调试Django或其他Python web服务器的一个原因是epdb.serve()命令。这将设置跟踪,并在您可以连接到的本地端口上提供该跟踪。典型用例:

我有一个视图,我想一步一步地讲。我将在我想要设置跟踪的位置插入以下内容。

import epdb; epdb.serve()

一旦执行了这段代码,我打开一个Python解释器并连接到服务实例。我可以分析所有的值,并使用标准pdb命令(如n, s等)逐级遍历代码。

In [2]: import epdb; epdb.connect()
(Epdb) request
<WSGIRequest
path:/foo,
GET:<QueryDict: {}>, 
POST:<QuestDict: {}>,
...
>
(Epdb) request.session.session_key
'i31kq7lljj3up5v7hbw9cff0rga2vlq5'
(Epdb) list
 85         raise some_error.CustomError()
 86 
 87     # Example login view
 88     def login(request, username, password):
 89         import epdb; epdb.serve()
 90  ->     return my_login_method(username, password)
 91
 92     # Example view to show session key
 93     def get_session_key(request):
 94         return request.session.session_key
 95

您可以在任何时候了解更多关于输入epdb帮助的信息。

如果希望同时为多个epdb实例提供服务或连接到多个epdb实例,可以指定监听的端口(默认为8080)。即。

import epdb; epdb.serve(4242)

>> import epdb; epdb.connect(host='192.168.3.2', port=4242)

如果没有指定,主机默认为'localhost'。我在这里介绍它是为了演示如何使用它来调试本地实例以外的东西,比如本地LAN上的开发服务器。显然,如果您这样做,请注意设置跟踪永远不会出现在您的生产服务器上!

作为一个快速提示,您仍然可以使用epdb执行与接受的答案相同的操作(import epdb;epdb.set_trace()),但我想强调一下服务功能,因为我发现它非常有用。

调试Django代码的最佳选择之一是通过wdb: https://github.com/Kozea/wdb

wdb works with python 2 (2.6, 2.7), python 3 (3.2, 3.3, 3.4, 3.5) and pypy. Even better, it is possible to debug a python 2 program with a wdb server running on python 3 and vice-versa or debug a program running on a computer with a debugging server running on another computer inside a web page on a third computer! Even betterer, it is now possible to pause a currently running python process/thread using code injection from the web interface. (This requires gdb and ptrace enabled) In other words it's a very enhanced version of pdb directly in your browser with nice features.

安装并运行服务器,并在代码中添加:

import wdb
wdb.set_trace()

作者认为,pdb的主要区别是:

For those who don’t know the project, wdb is a python debugger like pdb, but with a slick web front-end and a lot of additional features, such as: Source syntax highlighting Visual breakpoints Interactive code completion using jedi Persistent breakpoints Deep objects inspection using mouse Multithreading / Multiprocessing support Remote debugging Watch expressions In debugger code edition Popular web servers integration to break on error In exception breaking during trace (not post-mortem) in contrary to the werkzeug debugger for instance Breaking in currently running programs through code injection (on supported systems)

它有一个很棒的基于浏览器的用户界面。一种使用的乐趣!:)

从我的角度来看,我们可以将常见的代码调试任务分解为三种不同的使用模式:

Something has raised an exception: runserver_plus' Werkzeug debugger to the rescue. The ability to run custom code at all the trace levels is a killer. And if you're completely stuck, you can create a Gist to share with just a click. Page is rendered, but the result is wrong: again, Werkzeug rocks. To make a breakpoint in code, just type assert False in the place you want to stop at. Code works wrong, but the quick look doesn't help. Most probably, an algorithmic problem. Sigh. Then I usually fire up a console debugger PuDB: import pudb; pudb.set_trace(). The main advantage over [i]pdb is that PuDB (while looking as you're in 80's) makes setting custom watch expressions a breeze. And debugging a bunch of nested loops is much simpler with a GUI.

啊,是的,模板的问题。最常见的问题(对我和我的同事来说)是错误的上下文:要么你没有变量,要么你的变量没有某些属性。如果你正在使用调试工具栏,只检查“模板”部分的上下文,或者,如果这还不够,在你的上下文填充后,在视图的代码中设置一个断点。

就这样。

我使用pyDev与Eclipse真的很好,设置断点,进入代码,查看任何对象和变量的值,尝试它。