Intro to Python CSSU Nov/28/2007 By Georgi Petrov & Atanas Dyulgerov

Outline What is Python Python Advantages Who uses Python Syntax & Semantics Data Structures Python Standard Library Demo 1 Object Orientation Demo 2

What is Python

Python Advantages

Who uses Python

Syntax & Semantics

Data Structures

Python Standard Library

Demo 1

Object Orientation

Demo 2

What is Python? interpreted, interactive, object-oriented programming language Widely used in the industry Cousin of Tcl, Perl and VB Used in web programming and in standalone applications

interpreted, interactive, object-oriented programming language

Widely used in the industry

Cousin of Tcl, Perl and VB

Used in web programming and in standalone applications

Python Advantages Elegant syntax Safe Object-oriented Powerful Portable Free

Elegant syntax

Safe

Object-oriented

Powerful

Portable

Free

Python is simple print &quot;Hello World!&quot; #include <iostream.h> int main() { cout << &quot;Hello World!&quot;; } public class helloWorld { public static void main(String [] args) { System.out.println(&quot;Hello World!&quot;); } } Python C++ Java

public class helloWorld

{

public static void main(String [] args)

{

System.out.println(&quot;Hello World!&quot;);

}

}

Python is fun & practical Lack of type declaration Huge library of modules Widespread use in industry Available for all the major platforms (Windows, MacOS, Linux, Unix, BeOS, Java)

Lack of type declaration

Huge library of modules

Widespread use in industry

Available for all the major platforms (Windows, MacOS, Linux, Unix, BeOS, Java)

Who uses Python Google NASA Rackspace Industrial Light & Magic

Google

NASA

Rackspace

Industrial Light & Magic

Syntax - Indentation

Syntax - Operators Comparison Operators ==, <, >, <=, >= Logical Operators Zero values are treated as “”, 0, None, 0.0, [] and {}

Comparison Operators ==, <, >, <=, >=

Logical Operators Zero values are treated as “”, 0, None, 0.0, [] and {}

Data Structures Base Types integer, float, long integer, octal integer, hexadecimal integer, complex, character string, list, dictionary, tuples, file Collection types sequences & mappings Object system

Base Types integer, float, long integer, octal integer, hexadecimal integer, complex, character string, list, dictionary, tuples, file

Collection types

sequences & mappings

Object system

Python Standard Library The greatest strengths of Python Hundreds of modules Examples Syntax: import email email , math , calendar , HTMLParser

The greatest strengths of Python

Hundreds of modules

Examples

Syntax: import email

Object Oriented Mechanism Similar to C++ and Java Supports multiple inheritance Polymorphism No private class members  class Stack: def __init__(self,size): self.data = [None]*size self.size = 0 def push(self,item): self.data[self.size] = item self.size = self.size + 1 def pop(self): self.size = self.size - 1 return self.data[self.size] def is_empty(self): return self.size == 0 def is_full(self): return self.size == len(self.data)

Similar to C++ and Java

Supports multiple inheritance

Polymorphism

No private class members 

Demo 1 Adjusting Apache to read Python Sample “Hello World” script

Adjusting Apache to read Python

Sample “Hello World” script

Object Orientation Defining classes class SomeClass: &quot;Just some class...that's all.&quot; Adding data members and methods class SomeClass &quot;Just some class...that's all.&quot; someNumber = 2131 def someFunction ( self ): return someNumber

Defining classes

class SomeClass:

&quot;Just some class...that's all.&quot;

Adding data members and methods

class SomeClass

&quot;Just some class...that's all.&quot;

someNumber = 2131

def someFunction ( self ):

return someNumber

Object Orientation Self Instantiating myObject = myClass() ‏ Calling and addressing myObject.someFunction() ‏ Deletion del myObject.someNumber

Self

Instantiating

myObject = myClass() ‏

Calling and addressing

myObject.someFunction() ‏

Deletion

del myObject.someNumber

Object Orientation Constructors class AnotherClass: def __init__ ( self, anotherArgument ): self.anotherArgument = anotherArgument Single/Multiple Inheritance and Overriding class ParentClass: def print( self ): print “parent” class ChildClass ( ParentClass ): def print( self ): print “child”

Constructors

class AnotherClass:

def __init__ ( self, anotherArgument ):

self.anotherArgument = anotherArgument

Single/Multiple Inheritance and Overriding

class ParentClass:

def print( self ):

print “parent”

class ChildClass ( ParentClass ):

def print( self ):

print “child”

Demo 2 Brief networking info Sockets SocketServer Framework Ports and Addresses Demo

Brief networking info

Sockets

SocketServer Framework

Ports and Addresses

Demo

References http://wiki.python.org http://www.python.org/ http://en.wikipedia.org/wiki/Python_(programming_language)

http://wiki.python.org

http://www.python.org/

http://en.wikipedia.org/wiki/Python_(programming_language)

Thank You Q & A

Q & A