| Author: | Atul Varma |
|---|---|
| Copyright: | This document has been placed in the public domain. |
pymdev is a simple Python module that uses pymacs, a tool that allows both-way communication between Emacs Lisp and Python, to provide Python development tools in Emacs.
The idea for pymdev was largely inspired by Jef Raskin's "The Humane Environment", now known as Archy. In Archy, Python code can be executed anywhere; you simply select code and issue the "run" command on it. This essentially obviates the need to switch to a separate Python interpreter application; whether you were writing an email or a term paper or developing software in Archy, you could harness the power of Python anywhere, at any time, simply by selecting text and issuing a "run" command.
Since Archy was very much a prototype not ready for real-world use, I decided that the text editor I used for most of my work, Emacs, could use similar functionality, so I created pymdev.
pymdev goes beyond the implementation of a simple "run" command by using Python's introspection and documentation-testing capabilities to aid in the development of Python code. See the "Usage" section of this document for more information.
pymdev can be downloaded from the following location:
http://www.toolness.com/pymdev/pymdev.py
pymdev has been tested on Python 2.4.
You will also need pymacs installed and set up:
http://pymacs.progiciels-bpi.ca/manual/index.html
Optionally, you can also install autoimp if you'd like the Python code execution functions to automatically have all your packages in their global namespace:
http://www.princeton.edu/~csbarnes/code/autoimp
However, pymdev will still work fine without autoimp installed.
First, copy the pymdev.py file to your site-packages directory.
You will also need to add at least the following line to your .emacs file:
(pymacs-load "pymdev" "pymdev-")
You also may want to bind some of pymdev's exported emacs functions to keys. Personally, I've abandoned the traditional use of ctrl-z for suspending emacs and replaced it for accessing my pymdev functions:
(define-key global-map [(control z)] nil) (global-set-key [(control z) (control z)] 'pymdev-eval-region-to-minibuffer) (global-set-key [(control z) (control r)] 'pymdev-eval-region-in-place) (global-set-key [(control z) (control i)] 'pymdev-eval-region-insert) (global-set-key [(control z) (control x)] 'pymdev-exec-and-doctest-region) (global-set-key [(control z) (control h)] 'pymdev-help-on-region) (global-set-key [(control z) (control d)] 'pymdev-doctest-region)
The following are lisp functions usable from Emacs.
pymdev-eval-region-to-minibuffer
This function evaluates the current region as a Python expression, placing the result in the minibuffer.
pymdev-eval-region-in-place
This function evaluates the current region as a Python expression, replacing the region with the result of the evaluation.
pymdev-eval-region-insert
This function evaluates the current region as a Python expression and inserts the result into the current buffer at the cursor position, prepending the result with an equals sign.
pymdev-exec-and-doctest-region
This function executes the current region as a Python statement or series of statements.
stdout and stderr are redirected to an emacs buffer called 'Python output'.
If any of the objects produced by the selected code (functions, classes, etc) have doctests, they are executed automatically, and any errors in them are placed in an emacs buffer called 'Doctest output'.
pymdev-help-on-region
Evaluates the current region as a Python expression and provides you with context-sensitive help on the result.
If the result of the expression is a module, function, class, or anything with a docstring, the documentation for it will be placed in a new buffer called 'Python documentation'.
If the result of the expression is a dictionary, its keys will be listed in the minibuffer.
If the expression is followed by a period ('.'), this function will work somewhat similarly to the 'autocomplete' mechanism of an IDE: it will inspect the result of the expression and present you with a list of members from which you can select. The item you select will be inserted at the cursor location (i.e., after the '.').
Note that this function actually evaluates the text denoted by the given region, so if any of the functions have side effects, they will manifest themselves!
pymdev doesn't currently respond very well if the result of an evaluation contains non-ASCII characters.
I'm not a big fan of the distinction in this module between "evaluating" Python expressions and "executing" Python statements: it forces me to think about whether the Python code I've selected is an expression or a statement. I'd rather have that be auto-detected, or something similarly humane.
I'd like to integrate statistics about code coverage for statement execution/doctests, as well as some kind of pychecker support.
Please feel free to send questions, comments, bug reports, and other correspondence regarding pymdev to varmaa@gmail.com.
This software has been contributed to the public domain.