Variables and their uses in Python

Variable:
A variable is nothing but a reserved memory location to store values

Assignment
a = 100
print a

a="sangeeth"
b = 1309
print a+str(b)

Advantage:
Reuse, Delete variables

Reuse Variables:
a = 100
print a

a="san"
print a

Delete Variables:

w 100
a =140

delete w
print a

Accessing Variables Values
var1 = "Sangeeth"
var2 = "Pythin Testing in http://pythonfiddle.com/"
print "Print var1[0]:",var1[0]
print "Print var2[1:6]:",var2[1:6]

Operators:
[] - Return letters in specified Index.
[ : ] - Return letters from given range in specified Index.
in - Return true if specified char or set of char in string is present else False(ex: s= "sangeeth" print "ee" in s).
not in - Same as above, but not present in string.
+ - It concatenates two strings
r/R - Raw string suppresses actual meaning of escape characters.
%r - It insert the canonical string representation of the object (i.e., repr(o)) 
%s- It insert the presentation string representation of the object (i.e., str(o)) 

%d- it will format a number for display
* - Repeat (ex: x="Sangeeth" 
y=3
print x*y


String Variables Replace:
str1 = 'I miss Australia' 
str2 = str1.replace('miss', 'will go')
print(str2)

Output:
I will goAustralia


Change Casing in String:
string="I m in Australia"

print string.upper()

Print string.capitalize()  # It capitalize only first letter of string

String within String:
print " sangeeth ".join("sangeeth")

Reversing String:
string="Sangeeth"

print ''.join(reversed(string))

Split String:
string="sangeeth is a good boy"

print string.split(' ')