Open source general-purpose. Multiplatform programming language
Object Oriented, Procedural, Functional
Easy to interface with C/ObjC/Java/Fortran
Easy to interface with C++ (via SWIG)
Great interactive environment
Python 'philosophy' emphasis readability, clarity and simplicity
The Interactive Interpreter
Source can be compiled or run just-in-time
it is very easy to learn and understand
It is extensible, you can easily plug new modules in your Python installation and extend its functionality
Python is a very flexible language. It is widely used for many different purposes. Typical uses include :
Web Programming
System administration tasks via simple scripts
Desktop Applications
Windows Applications
Natural Language ToolKit
Large collection of proven modules included in the standard distribution
Offers Matlab-ish capabilities within Python
Fast array operations
2D arrays, multi-D arrays, linear algebra etc.
Wrappers for Astronomical Packages
Installing Python
Download Python 3.5(32-bit and 64-bit versions of the interpreter ) which includes:
Python Software :
The standard library, test suite, launcher and pip will be installed
Development Environment
IDLE – a cross-platform Python development environment. Text editor with color-coding and smart indenting for creating python files Menu commands for changing system settings and running files. Shell for interactive evaluation.
Do not use Notepad - it is a bad choice because it does not do syntax highlighting and also importantly it does not support indentation of the text
Why IDLE
IDLE helps you program in Python by:
color-coding your program code
debugging
auto-indent
interactive shell
Write simple Python program
program 1 : #one.py
print('Hello World')
Ruuning python program in IDLE
Open New Window , enter program and save
Run and Run Module
Ruuning python program in command line
>> python one.py
Outpur :
Hello World
program2 : # kbinput.py
name = input('What is your name:')
print('It is good to meet you mr ', name)
Whitespace:
Whitespace is important in Python. Actually, whitespace at the beginning of the line is important. This is called indentation. Leading whitespace at the beginning of the logical line is used to determine the indentation level.
This means that statements which go together must have the same indentation. Each such set of statements is called a block.
You cannot arbitrarily start new blocks of statements (except for the default main block which you have been using all along, of course).
How to indent:
Do not use a mixture of tabs and spaces for the indentation as it does not work across different platforms properly. Use a single tab or four spaces for each indentation level.
Note :Python will always use indentation for blocks and will never use braces
Comment:
Single line : Start comments with # – the rest of line is ignored
Multi line : “““This is the multi line comment .”””
Program 3: command.py
# Using If and elif Statement - compute.py
a = input('enter value a:')
b = input('enter value b:')
x= int(a)
y=int(b)
ch = input('enter your option(1.add 2.subtract):')
choice= int(ch)
if choice == 1:
print('sum of ' + a + 'and ' + b +'=', x+ y )
elif choice == 2:
print ( ' subtraction of '+ a + ' and ' + b + 'is ' , x- y )
else:
print('Invalid Option:')
Program 4 : inputText.py
x = input(‘enter char:’)
while( x != ‘quit'):
x = input(‘Enter quit for exit):')
if(x=='z'):
break
print(x)
print('done')
Program 5 : usingFor.py
val=input('enter the value for x')
x=int(val)
for i in range(x):
if(i%2==0):
continue
print(‘value:’,i)
print('done')
Program 6 : sort.py
number=[8,5,4,3,6,3,1,2]
index=len(number)
for i in range(index):
for j in range(i+1,index):
if number[i]>number[j]:
temp=number[i]
number[i]=number[j]
number[j]=temp
print(number)
print('numbers',':sort completed:')
Program : recursive.py
def printdata(msg,n):
if n<=0:
return
else:
print(msg)
printdata(msg,n-1)
printdata('hello',6)
def countup(start,end):
if start>=end:
return
print(start)
else:
print(start)
start=start+1
countup(start,end)
countup(5,15)