Anyone who learned to code in the mid to late 80s probably spent some time with a Borland compiler -- probably either Turbo Pascal or Turbo C. One of the best features of the Turbo compilers was their IDE -- and in particular, a really good visual debugger that would let you inspect code while it was running.
Then we all moved to Unix, and somehow forgot what a good debugger was. GDB is perfectly functional, but isn't very intuitive. GDB gives you perfect control over the execution of your code, but bad contextual information to let you know what control you should be exercising.
Then came Python. Python's execution model contains excellent debugging hooks, and supplies PDB as a proof of concept. PDB is an interface that shares many similarities with GDB -- text mode, fantastic control, but very bad contextual information.
So - enter bugjar. A graphical interface for debugging code.
PDB, but with the context to help you step through code in a meaningful way.
Bugjar can be installed with pip:
$ pip install bugjar
You can then debug a Python script by typing the following at a shell prompt:
$ bugjar myscript.py arg1 arg2
This will start a graphical interface, with myscript.py loaded into the
source code window. You can set (or remove) breakpoints by clicking on line
numbers; you can step through and into code; or you can set the program
running unconstrained. Each time the debugger stops at a breakpoint, the
inspector will be updated with the current contents of locals, globals, and
builtins.
The Python script will run using your current environment; if you have an active virtualenv, that environment will be current.
When you quit the debugger, the script will be terminated.
Ubuntu's packaging of Python omits the idlelib library from it's base
packge. If you're using Python 2.7 on Ubuntu 13.04, you can install
idlelib by running:
$ sudo apt-get install idle-python2.7
For other versions of Python and Ubuntu, you'll need to adjust this as appropriate.
If you're running Cricket in a virtualenv, you'll need to set an environment variable so that Cricket can find the TCL graphics library:
$ set TCL_LIBRARY=c:\Python27\tcl\tcl8.5
You'll need to adjust the exact path to reflect your local Python install.
You may find it helpful to put this line in the activate.bat script
for your virtual environment so that it is automatically set whenever the
virtualenv is activated.
Documentation for bugjar can be found on Read The Docs.
Bugjar is part of the BeeWare suite. You can talk to the community through:
- @pybeeware on Twitter
- The pybee/general channel on Gitter.
We foster a welcoming and respectful community as described in our BeeWare Community Code of Conduct.
If you experience problems with bugjar, log them on GitHub. If you want to contribute code, please fork the code and submit a pull request.