How to debug a django application in a comfortable way? - python

I'm currently debugging a django application by inserting import pdb; pdb.set_trace() in the code and using the debugger commands to navigate through running application.
The debugger shows the current line, but most of the time it is helpful to have a bit more context. Therefore I open the current file in an editor in another window.
Now whenever the flow changes to another class I need to manually open the new file in the editor. - This feels like there is an easier way to do this.
Is there any kind of IDE integration able to debug a running django application?
Is there some other way I am not yet aware of?

PyCharm can do this. Perhaps only the Professional edition which is not free, but has a 30-days trial.

To make your life easier, try IDE like PyCharm.
I use pdb or ipdb to debug simple python file, but they wouldn't be so useful in debugging complex Python scripts.
Also, django-debug-tools is a good tool to debug and optimize Django application.

Related

Has PyDev an interactive shell (during debugging) as in Komodo?

so far I used the Komodo IDE for Python development, but I'm now testing Eclipse with PyDev. Everything works fine, but there is one Komodo feature that I'm missing.
In Komodo I can inspect the running application in a debugger shell. I.e. after hitting a breakpoint I can not only read the content of variables, but I can execute arbitrary Python code (e.g. changing the value of variables) and then continue program execution.
PyDev has also some interactive shell during debugging, but I can only read variables and not change their content. Is this feature not available in PyDev or am I missing something here?
Many thanks,
Axel
As you've seen, you can just use the console directly:
http://pydev.org/manual_adv_debug_console.html
Now, you can also connect the interactive console (which is a bit more advanced) by selecting a stack frame to attach it:
http://pydev.org/manual_adv_interactive_console.html
Yes you can do that. Just type in the console what ever commands you want :). I usually have to right click then
Debug As >> Python run
PyDev is a little bit quirky, but you get used to it.

python or pythonw in creating a cross-platform standalone GUI app

I am developing a simple standalone, graphical application in python. My development has been done on linux but I would like to distribute the application cross-platform.
I have a launcher script which checks a bunch of environment variables and then sets various configuration options, and then calls the application with what amounts to python main.py (specifically os.system('python main.py %s'% (arg1, arg2...)) )
On OS X (without X11), the launcher script crashed with an error like Could not run application, need access to screen. A very quick google search later, the script was working locally by replacing python main.py with pythonw main.py.
My question is, what is the best way to write the launcher script so that it can do the right thing across platforms and not crash? Note that this question is not asking how to determine what platform I am on. The solution "check to see if I am on OS X, and if so invoke pythonw instead" is what I have done for now, but it seems like a somewhat hacky fix because it depends on understanding the details of the windowing system (which could easily break sometime in the future) and I wonder if there is a cleaner way.
This question does not yet have a satisfactory answer.
If you save the file as main.pyw, it should run the script without opening up a new cmd/terminal.
Then you can run it as python main.pyw
Firstly, you should always use .pyw for GUIs.
Secondly, you could convert it to .exe if you want people without python to be able to use your program. The process is simple. The hardest part is downloading one of these:
for python 2.x: p2exe
for python 3.x: cx_Freeze
You can simply google instructions on how to use them if you decide to go down that path.
Also, if you're using messageboxes in your GUI, it won't work. You will have to create windows/toplevels instead.

Python editor that can connect to remote environment?

I set up an interactive python environment in an application. I can input commands and they will execute inside it, having access to the variables that live there.
The problem is that I coded a half-assed editor that allows only that. It doesn't have command history, code completion etc, because I didn't code a full IDE. However, I would like to be able to write code in that environment with a fancy editor.
The way I think it can work out is that an editor will have an interface/protocol for remote python sessions, and I will just have to implement a server in my application (instead of the simple editor) and be able to connect and run code.
I can implement any interface or protocol that I have to, but I can't find an IDE that has such a protocol defined (or an easy way to plug an extension that will serve as the client side).
Essentially, I want a python editor that has an option to call a function x whenever a command (can be multiline) finished typing, and another function y when an autocomplete request occurs.
I checked out some editors but couldn't find such a feature. Does anyone know of such a thing? It actually doesn't have to be a python editor, just support the hooks that i need.
Thanks!
Did you try integrating PyCrust into your application? See this SO question
Embedding a Python shell inside a Python program
rpyc sounds like something which could be useful to you. rpyc added support for IronPython in their latest release. PyScripter supports rpyc. Maybe this is the combo you are looking for?

How can I save / copy classes & functions I've written in the python interpreter?

How can you save functions/ classes you've writing in a python interactive session to a file? Specifically, is there a way in pydev / eclipse's interactive session (on a mac) to do this?
I just started learning python - and am enjoying using the interpreter's interactive session for testing and playing with modules I've written. However, I find myself writing functions in the interpreter, which I think, oh it would be cool to save that to my script files. How do I do this?
I tried:
import pickle
pickle.dump(my_function, open("output.p", "w"))
But it seems to be more of a binary serialization, or at least nothing that I could copy and paste into my code...
Are there ways to see the code behind classes & functions I've defined in the interpreter? And then copy them out of the interpreter?
Update:
Ok, here's what I've learned so far:
I missed the easiest of all - PyDev's interactive session in eclipse allows you to right click and save your session. Still have to remove >>>'s, but gets the job done.
IPython is apparently the way to go to do this.
How to save a Python interactive session? has more details.
The best environment for interactive coding sessions has to be IPython, in my opinion. It's built on and extends the basic Python interpreter with a lot of magic, including history. For example, you can issue the command %logstart to dump all subsequent input to a file, which still needs to be edited afterward before it will be a script, but gives you a lot to work with.
When installing IPython, don't forget pyreadline.
In general, however, it is best to write code in an IDE and then run it. IPython helps here as well. If you write and save the script, then use the IPython "run" command to run it, the entire global namespace of the script will be available for inspection in your IPython session. Additionally, you can use the -d argument to run to trigger the pdb debugger immediately on any unhandled exception.
If you're more of a straightlaced IDE and debugger kind of guy, then the easiest and best lightweight environment has to be PyScripter.
I think the answer is to change your workflow.
What I do is write my functions in an editor (emacs), and then press a key combination (Ctrl-c Ctrl-e) to send the region of text to the (i)python interpreter.
That way I can save the function if I want, and also play with it in an interpreter.
Emacs is central to how I do it, but I'm sure there must be similar approaches with many editors (vim, gedit, etc) and IDEs.
PS. Finding a good editor is crucial when working with Python. The editor must be able to move blocks of code to the left and right easily, or the whitespace issue becomes too onerous.
I dislike typing blocks of code in the python interpreter because it doesn't allow me to shift blocks easily. You'll like Python even more when you find the right editor.
You can setup a python history file which stores everything you type into the interpreter.
Here's how:
http://docs.python.org/tutorial/interactive.html
I think it can't be done.
Python can perform instrospection with the inspect module, but the inspect.getsource function won't work without a source file.

Creating an Python/py2app application that simply opens a terminal on launch?

I've written a nice Python application that is basically an HTTP proxy for SMS modems, and I'd like to make it a double-clickable application on Macs. So far I've been including a .commmand file which is double-clickable, which basically consists of
cd `dirname $0`
(sleep 8;open http://127.0.0.1:8080/)&
mac/slingshotsms.app/Contents/MacOS/slingshotsms
How can I make the main .app executable call a different place / or what's the easiest way to make an application that is basically a wrapper for a terminal utility and only displays its output? Currently double-clicking on the application will use the open utility on Macs - I want to emulate the behavior of double-clicking on Contents/MacOS/slingshotsms when double-clicking on the application icon. any tips?
If you're looking for 'easy', try just giving your python script a .command suffix, and make sure it's executable. For example:
#!/usr/bin/env python
# file: hello.command
print 'hello world'
If you're looking for 'polished', then you probably want to learn about Launch Services, PyObjC, Interface Builder, NIB files, app wrappers, and all sorts of Mac OS X-specific technology details. But, note that PyObjC is nearly impossible to use for anything non-trivial without already knowing, more or less, how to do the same task using the Objective-C Cocoa APIs. PyObjC is a fairly thin wrapper around those APIs, and you have to know the Cocoa idioms / design patterns to understand how the moving parts fit together.
If you don't actually need a terminal, but instead just want an app wrapper around a script, have a look at Platypus
Write an AppleScript application that launches Terminal and runs your Python script (which will be inside the application's bundle).

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