ByKarthik Prakash

• Introduction to Python

• Interactive “Shell”

• Basic Types and Containers

• Control Structures

“Remarkable power with very clear syntax”

Python is an Interpreted, Object Oriented Programming language.

…it’s named after a television series Monty Python’s Flying Circus

It was created by Guido Van Rossum in the year 1990…

Features :-

• Free and Open Source… Maintained by the PSF (Python Software Foundation)

• Rapid Prototyping

• Compiled to interpreted byte code .. sometimes called as Scripting language ….i.e Compilation is implicit

• Indentation for block structure…“Life's better without braces(Bruce Eckel)”

• Extremely Portable (Windows,Linux,Unix,Mac… etc)

• Powerful Standard libraries

Two variations: IDLE (GUI) and PYTHON (command line)

• Most Python implementations work on CLI (Command Line Interface)

• Great for learning the language by experimenting with the library

• Great for testing your own modules

• Benefits of IDLE

• Multi Windows Text Editor• Interactive Command Shell• Syntax Highlighting• Auto-Indentation• Auto Completion extended to Intellisence

• None• Numbers and Floats• Complex Numbers …. (i + j)• Floating point• Boolean…. True or False• “Strings”• u“Unicode”• Tuples ()• Lists []• Dictonaries {}

• Built-in Function “type()”

• If, else, elif….

• Try and except

• While Loop

• For Loop

• List Comprehension

• Functions

• Doc Strings … Smart way of Documenting modules

• File Handling …… read , write , append to file

Single

[ <item operation> for item in sequence <if condition>]

Nested

Special care has to be taken for the nested list comprehension:

….when nesting list comprehensions, read from right to left.

Function Definition :-

def name (arg1, arg2…. , argn)

“““ Documentation ””” #optional statements

. . .

return expression

name(arg1,arg2) # Call to <name>

File Modes

• Mode Meaning • 'r' open for reading (default)

• 'w' open for writing, truncating the file first

• 'a' open for writing, appending to the end of the file if it exists

• 'b' binary mode

f = open(filename, [mode])

• read(), readline(), readlines()

• write(), writelines()

• seek(pos), tell()

• close()

• Classes

o Class Definition

o Class Objects

o Class Data members

o Class Methods

o Class Inheritance

class Stack:"A well-known data structure…"def __init__(self): # constructorself.items = []def push(self, x):self.items.append(x) #. Push into the Stack…the sky is the limitdef pop(self):x = self.items[-1] # Pop from the stackdel self.items[-1]return xdef empty(self):return len(self.items) == 0 # Boolean result

object = Stack() #--- Object of the Class “Stack”

….. Constructor invoked during Object instantiation

object.push(arg1) #---- Call to Class Method “push”

print object.items #---- Access the Class Data Member

• class BaseClass:

baseDataVar = 10 def baseMethods(self) statements

class DerivedClass(BaseClass):

def Method() print self.baseDataVar self.baseMethods() #-- Call to base class method