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This tutorial teaches the fundamental concepts of symbolic debuggers. We will be using Winpdb to debug Python scripts. The concepts that you learn here, however, are fundamental to working with debuggers in general. At the end of the exercise, you should feel comfortable with using symbolic debuggers and have an inherent understanding of why these tools prove to reduce time and effort needed in debugging without altering the code itself to do so.

Easily create Google charts using python syntax and datasets. Python wrapper for the Google Chart API. The wrapper can render the URL of the Google chart, based on your parameters, or it can render an HTML img tag to insert into webpages on the fly. Made for dynamic python websites (Django,Zope,CGI,etc.) that need on the fly chart generation without any extra modules. The wrapper SHOULD also work with Eastwood the Google Chart API workalike. G = GChart('p3', [5,10])

One of the main difficulties I've had using parser generators has been the difficulty of figuring out why a grammar didn't work. Fixing shift-reduce and reduce-reduce conflicts seemed like voodoo to me, and though I slightly understand better how to fix such things now it's still a different mode of thinking that I don't want to try to get into when I just want to parse something simple. PyMeta uses a variation on the Parsing Expression Grammar (PEG) approach to parsing. The chief consequence of this is there's no possibility of ambiguity in a parse: a successful parse will yield exactly one result, and you can trace the control flow through the grammar to figure out how it got there.

Louie provides Python programmers with a straightforward way to dispatch signals between objects in a wide variety of contexts. It is based on PyDispatcher, which in turn was based on a highly-rated recipe in the Python Cookbook. Louie is licensed under The BSD License.

Following my thoughts yesterday, here are some VIM python scripts to add python breakpoint and debugging features to VIM. With this set up the F7 key will set a breakpoint on a line of code, Shift-F7 will remove all breakpoints and Shift-F12 will execute a script in the python debugger. This only runs on windows as far as I know, because it uses the 'start' command to launch the debugger in a seperate process without VIM waiting for it to finish. This allows you to look through the source code (and fix it) while the debugging is still in progress.

Install using binary installer Download installer from http://ipython.scipy.org/dist/pyreadline-1.3.win32.exe make sure no other readline is installed run installer The configuration file pyreadlineconfig.ini can be copied from Python24/lib/site-packages/pyreadline/configuration to your HOME directory (usually c:/documents and settings/YOURNAME). When using ipython pyreadline is automatically activated. If you want to use pyreadline from the interactive prompt of the python interpreter then you have to include the code in Python24/lib/site-packages/pyreadline/configuration/startup.py in your pythonstartup file or set the PYTHONSTARTUP environment variable to point to that file. Manual can be found in Python24/share/doc/pyreadline

aspects.py library provides means to intercept function calls. Functions and methods (also in Python standard library and third party code) can be wrapped so that when they are called, the wrap is invoked first. Depending on the wrap, the execution of the original function can be omitted, or the function can be called arbitrarily many times. Wraps are able to modify the arguments and the return value of the original function. In the terminology of aspect-oriented programming, the library allows applying advices (wraps) to call join points of methods and functions in around fashion.

I love python for its beautiful code and practicality. But it’s not going to win a pure speed race with most languages. Most people think of speed and ease-of-use as polar opposites - probably because they remember the pain of writing C. Cython tries to eliminate that duality and lets you have python syntax with C data types and functions - the best of both worlds. Keeping in mind that I’m by no means an expert at this, here are my notes based on my first real experiment with Cython:

One of my recent research tasks required me to retrieve various information from del.icio.us, a well-known social bookmarking service. My programming language of choice is Python, and so I wrote a basic Python module for getting the data I needed.

> Is there a way to find the number of processors on a machine (on linux/ > windows/macos/cygwin) using python code (using the same code/cross > platform code)? From processing <http://cheeseshop.python.org/pypi/processing/0.34> : def cpuCount():     '''     Returns the number of CPUs in the system     '''     if sys.platform == 'win32':         try:             num = int(os.environ['NUMBER_OF_PROCESSORS'])         except (ValueError, KeyError):             pass     elif sys.platform == 'darwin':         try:             num = int(os.popen('sysctl -n hw.ncpu').read())         except ValueError:             pass     else:         try:             num = os.sysconf('SC_NPROCESSORS_ONLN')         except (ValueError, OSError, AttributeError):             pass     if num >= 1:         return num     else:         raise NotImplementedError --

 > According to the fact that all Thread run on the same CPU (if i didn't  > understand wrong), i'm asking if python will suffer from the future  > multicore CPU. Will not python use only one core, then a half or a  > quarter of CPU ? It could be a serious problem for the future of python... I agree that it could potentially be a serious hindrance for cpython if "multiple core" CPUs become commonplace. This is in contrast to jython and ironpython, both of which support multiple-cpu parallelism. Although I completely accept the usual arguments offered in defense of the GIL, i.e. that it isn't a problem in the great majority of use cases, I think that position will become more difficult to defend as desktop CPUs sprout more and more execution pipelines. I think that this also fits in with AM Kuchling's recent musing/thesis/prediction that the existing cpython VM may no longer be in use in 5 years, and that it may be superceded by python "interpreters" running on top of other VMs, namely the JVM, the CLR, Smalltalk VM, Parrot, etc, etc, etc. http://www.amk.ca/diary/archives/cat_python.html#003382 I too agree with Andrew's basic position: the Python language needs a period of library consolidation. There is so much duplication of functionality out there, with the situation only getting worse as people re-invent the wheel yet again using newer features such generators, gen-exps and decorators.

SendKeys SendKeys(keys, pause = 0.05, with_spaces = False, with_tabs = False, with_newlines = False, turn_off_numlock = True) Parameters keys : str A string of keys. pause : float The number of seconds to wait between sending each key or key combination. with_spaces : bool Whether to treat spaces as {SPACE}. If False, spaces are ignored. with_tabs : bool Whether to treat tabs as {TAB}. If False, tabs are ignored. with_newlines : bool Whether to treat newlines as {ENTER}. If False, newlines are ignored. turn_off_numlock : bool Whether to turn off NUMLOCK before sending keys.

Key Code BACKSPACE {BACKSPACE}, {BS}, or {BKSP} BREAK {BREAK} CAPS LOCK {CAPSLOCK} or {CAP} DEL or DELETE {DELETE} or {DEL} DOWN ARROW {DOWN} END {END} ENTER {ENTER} or ~ ESC {ESC} HELP {HELP} HOME {HOME} INS or INSERT {INSERT} or {INS} LEFT ARROW {LEFT} NUM LOCK {NUMLOCK} PAGE DOWN {PGDN} PAGE UP {PGUP} PRINT SCREEN {PRTSC} RIGHT ARROW {RIGHT} SCROLL LOCK {SCROLLLOCK} SPACE BAR {PACE} TAB {TAB} UP ARROW {UP} F1 {F1} F2 {F2} F3 {F3} F4 {F4} F5 {F5} F6 {F6} F7 {F7} F8 {F8} F9 {F9} F10 {F10} F11 {F11} F12 {F12} F13 {F13} F14 {F14} F15 {F15} F16 {F16} F17 {F17} F18 {F18} F19 {F19} F20 {F20} F21 {F21} F22 {F22} F23 {F23} F24 {F24} Keypad add {ADD} Keypad subtract {SUBTRACT} Keypad multiply {MULTIPLY} Keypad divide {DIVIDE} Left Windows(R) {LWIN} Right Windows(R) {RWIN}