To use try except for error handling

try:
      s=0
      g=s/0   # Division by zero creates error
      print 'Value of g :',g

except:
      print 'Something went wrong.'



try:
      s=0
      g=s/10   # Division by zero by 10  creates no error
      print 'Value of g :',g

except:
      print 'Something went wrong.'

Decimal Number to Binary number conversion

n=int(raw_input('Enter the Number'))
h=" "
while n>0:
  n1=n%2
  print 'R',n1
  n=n/2
  print 'V=',n
  h=h+str(n1)
print 'Binary Number is:',h[::-1]
 

Binary Number to Decimal Conversion

k=int(raw_input('Enter the binary number:'))
b=k
c=0
while b>0:
  b=b/10
  c=c+1
print c  
n=0
sum=0
while n<c:
  r=k%10
  k=k/10
  sum=sum + (r*(2**n))
  n=n+1
print 'Decimal Number is:', sum

Trigonometric Functions

import math
d=int(raw_input('Enter the angle in degree:'))
x= math.radians(d)
print 'Corresponding Radians is:',x           #Converts angle from degrees to radians.
f1=math.acos(x)                                                          # Return the arc cosine of x
print 'acos',f1
f2=math.asin(x)                                                           #Return the arc sine of x
print 'asin',f2
f3=math.atan(x)                                                          #Return the arc tangent of x
print 'atan',f3
f4=math.cos(x)                                                            #Return the cosine of x
print 'cos',f4
f5=math.sin(x)                                                             #Return the sine of x
print 'sin',f5
f6= math.tan(x)                                                            # Return the tangent of x
print 'tan',f6

u=int(raw_input('Enter the value of x:'))
v=int(raw_input('Enter the value of y:'))
e=math.hypot(u, v)                                                 #Return the Euclidean norm, sqrt(u*u + v*v)
print 'The Euclidean norm:',e

Accessing Values in Strings and Updating

var = 'Python Programming'
print "var[0]: ", var[0]
print "var[3:9]: ", var[3:9]
print "var[1:5]: ", var[1:5]
print "var[:]: ", var[:]           # List all elements in string
print "var[:2]: ", var[:2]       # List first 2 elements in string
print "var[2:]: ", var[2:]      # Except first 2 elements in string
print "var[::-1]: ", var[::-1]  # String Reverse
j=len(var)
print 'Length of string is:',j
i=0
while i<j:
      print 'Character in the string is:', var[i]
      i=i+1

x = 'Hello World!'

print "Updated String :- ", 'New ' + x[6:12]

Simple calculator using if elseif else and nested if else

a=int(raw_input('Enter the value of a:'))
b=int(raw_input('Enter the value of b:'))
print ' 1. add  2.sub  3.mul  4. div  5.exp'
n=int(raw_input('Enter the choice:'))
if n==1:
      c=a+b
      print 'Added value is:',c
elif n==2:
      if a>b:     #Nested if else
            c=a-b
            print 'Subtracted value is:',c
      else:
            c=b-a
            print 'Subtracted value is:',c
elif n==3:
      c=a*b
      print 'Multiplication value is:',c
elif n==4:
      if b==0:          #Nested if else
            print 'Division by zero not defined'
      else:
            c=float(a)/b
            print 'Divison value is:',c
elif n==5:
      c=a**b
      print 'Exponent value is:',c
else:
      print 'Invalid options'

Factorial using while loop

f=i=1
n=int(raw_input('Enter the number: '))
while i<=n:
      f=f*i
      i=i+1
print f

To check the number is Prime or Not

n=int(raw_input('Enter the number to check:'))
flag=0
i=2
while(i<=(n/2)):
    if (n%i==0):
        flag=1
    i=i+1
if(flag==0):
    print  'The number ',n, ' is prime number'
else:
    print 'The number ',n, ' is not prime number'

Factorial using Recursion

def recur_factorial(n):
   if n == 1:
       return n
   else:
       return n*recur_factorial(n-1)


num = int(input("Enter a number: "))

if num < 0:
   print("Sorry, factorial does not exist for negative numbers")
elif num == 0:
   print("The factorial of 0 is 1")
else:
   print("The factorial of",num,"is",recur_factorial(num))

Searching the character count from string

word = raw_input('Enter the String:')
char = raw_input('Enter the Character to search:')

count = 0
for letter in word:
 if letter == char:
  count = count + 1
print 'Number of times repeated:', count