20061216 python intro

Python, A Charming Language


hzmangel@bupt

Multimedia Technology Teaching and Researching CenterBUPT

December 13, 2006


Contents

1 A Brief Intro to Python

2 Application Domains

3 Playing with Others

4 To be Pythonic

5 Some Demos

6 Networks Resources


A Brief Intro to Python

The Definitions

Two Definitions

Python is one of those rare languages which can claim to beboth simple and powerful. You will find it easy to concentrateon the solution to your problem rather than having toconcentrate on the programming language.

Python is an easy to learn, powerful programming language.It has efficient high-level data structures and a simple buteffective approach to object-oriented programming. Python’selegant syntax and dynamic typing, together with itsinterpreted nature, make it an ideal language for scripting andrapid application development in many areas on mostplatforms.



The History

The History for Python

Guido van Rossum, the creator of the Python language.

Xmas day in 1989.

BBC show “Monty Python’s Flying Circus”



Features

Features of Python I

Simple:Python is a simple and minimalistic language. Reading a goodPython program feels almost like reading English, althoughvery strict English. This pseudo-code nature of Python is oneof its greatest strengths.

Easy to Learn:Python is extremely easy to get started with, it has anextraordinarily simple syntax.

Free and Open Source:Python is an example of a FOSS(Free and Open SourceSoftware).



Features

Features of Python II

High-level Language:When you write programs in Python, you do not have toworry about low-level details such as managing the memoryused by your program, etc.

Protable:Python has been ported to many platforms, All your Pythonprograms can work on most of these platforms withoutrequiring any changes at all, if you are careful enough to avoidany system-specific features.

Interpreted:Python does not need compilation to a binary. It converts thesource code to a bytecodes file.



Features

Features of Python III

Object-oriented:Python supports procedure-oriented programming as well asobject-oriented programming.

Extensible:Python can use the code written in C/C++.

Embeddable:You can embed Python within your C/C++ programs to give’scripting’ capabilities for your program’s users.

Extensive Libraries:The Python Standard Library is huge, and there are a hugenumber of high-quality libraries available for Python.


Application Domains

Many Application Domains

GUI, network

Graphic and image process

Document process

Game development

Website

Scientific computing

...


Application Domains

GUI Libraries

GUI Libraries

Tcl/tk

wxPython

PyGTK

PyQT

PySWT


Application Domains

Network Development

Network Development

socket module

High-level network module

SocketServer, BaseHTTPServer, CGIHTTPServer, ...email, ftplib, telnetlib, ...

twisted

jabber library

Python-QQ


Application Domains

Graphics and Images

Graphics and Images

PIL: Python Imaging Library

PyOpenGL

Blender

matplotlib

yapgvb


Application Domains

Document Process

Document Process

epydoc

ReportLab


Application Domains

Game Development

Game Development

pygame


Application Domains

Web Development

Web Development

mod python + Apache

zope/plone

karrigell

cherrypy

django


Application Domains

Scientific Computing


numarray

numeric


Playing with Others

Playing with Others

COM

Python for Windows extensions

.NET

IronPython, Python for .NET

Java

Jython


To be Pythonic

Zen of Python

Beautiful is better than ugly.

Explicit is better than implicit.

Simple is better than complex.

Complex is better than complicated.

Flat is better than nested.

Sparse is better than dense.

Readability counts.

Special cases aren’t special enough to break the rules.

Although practicality beats purity.

Errors should never pass silently.

Unless explicitly silenced.

In the face of ambiguity, refuse the temptation to guess.

There should be one-- and preferably only one --obvious way to do it.

Although that way may not be obvious at first unless you’re Dutch.

Now is better than never.

Although never is often better than *right* now.

If the implementation is hard to explain, it’s a bad idea.

If the implementation is easy to explain, it may be a good idea.

Namespaces are one honking great idea -- let’s do more of those!

-- by Tim Peters


Some Demos

Some Demos

The slides followed will show some demos.

Almost all of them are copy from the turtiol


Some Demos

GUI Development

wxPython: Python + wxWidgets

import wx

class MyFrame(wx.Frame):

def __init__(self, parent, id, title):

wx.Frame.__init__(self, parent, id, title)

class MyApp(wx.App):

def OnInit(self):

frame = MyFrame(None, -1, "This is a test")

frame.Show(True)

self.SetTopWindow(frame)

return True

def main():

app = MyApp(0)

app.MainLoop()

if __name__ == "__main__":

main()


Some Demos

GUI Development

Screenshot

Figure: A simplewxPython app


Some Demos

GUI Development

BOA Constructor

Wiritten in Python

A Python IDE and wxPython GUI Builder

http://boa-constructor.sourceforge.net


Some Demos

GUI Development

Some Screenshots of BOA I

Figure: Frame Design


Some Demos

GUI Development

Some Screenshots of BOA II

Figure: Source Edit


Some Demos

GUI Development

Some Screenshots of BOA III

Figure: Debugger


Some Demos

GUI Development

Some Screenshots of BOA IV

Figure: UML View


Some Demos

Image Process

PIL: Python Image Library

Support many file format.

Provide powerful image processing and graphics capabilities.

Include filter, enchancement, ...

Export PostScript file.


Some Demos

Image Process

Demo Code

import Image

import ImageFilter

import ImageEnchance

im = Image.open("lenna.jpg")

im_rotate = im.rotate(45)

im_resize = im.resize(128, 128)

im_crop = im.crop((0, 0, 256, 256))

im_trans = im.transpose(Image.FLIP_LEFT_RIGHT)

r,g,b = im.split()

im_edge = im.filter(ImageFilter.FIND_EDGES)

im_enh = ImageEnhance.Contrast(im)

enh.enhance(1.3).show().


Some Demos

Image Process

Some Results


Some Demos


SciPy: Scientific Tools for Python

Pronounced Sigh Pie

Core library is NumPy

Provides many user-friendly and efficient numerical routines

http://www.scipy.org


Some Demos


A Simple Program

from enthought.chaco.wx import plt

from scipy import arange, optimize, special

plt.figure()

plt.hold()

w = []

z = []

x = arange(0,10,.01)

for k in arange(1,5,.5):

y = special.jv(k,x)

plt.plot(x,y)

f = lambda x: -special.jv(k,x)

x_max = optimize.fminbound(f,0,6)

w.append(x_max)

z.append(special.jv(k,x_max))

plt.plot(w,z, ’ro’)

from scipy import interpolate

t = interpolate.splrep(w, z, k=3)

s_fit3 = interpolate.splev(x,t)

plt.plot(x,s_fit3, ’g-’)

t5 = interpolate.splrep(w, z, k=5)

s_fit5 = interpolate.splev(x,t5)

plt.plot(x,s_fit5, ’y-’)


Some Demos


The Result

Figure: Result of SciPy Demo


Some Demos

Game Demo

PyGame

A set of Python modules

Designed for writing games

Written on top of SDL library


Networks Resources

Forums and Groups

Forums and Groups

http://www.python.org

http://python.cn

http://www.woodpecker.org.cn

http://groups.google.com/group/python-cn

http://www.python.org

http://python.cn

http://www.woodpecker.org.cn

http://groups.google.com/group/python-cn


Networks Resources

Python Powered Websites

Websites Powered by Python

http://moinmoin.wikiwikiweb.de

http://www.douban.com

http://moinmoin.wikiwikiweb.de

http://www.douban.com


Networks Resources


Q&A

Q & A


Networks Resources


Thanks

Thanks

20061216 python intro

Technology

python language

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denitions python

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python guido van rossum

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