Python Programs using conditional and looping constructs

Example

for val in numbers:

val=val+1

Similarly, we can have for loop with

else statement

Syntax

for variable in sequence:

      Body of for loop

else:

       Statement

Example

for i in myList:

       print(i)

else:

       print("The number is not present in your list")

Ex. 10

Write a python program to find the sum of 1 to 10 numbers.

Solution :

print("Enter the value of n")

n = int(input())

sum = 0

for i in range(1,n+1):

      sum =  sum+i

print("The sum of ",n,"numbers is ",sum)

Output

Enter the value of n

5

The sum of 5 numbers is

15

Ex. 11

Write a python program to display the multiplication table.

Solution:

print("Enter number for its multiplication table")

n=int(input())

for i in range(1,11):

         print(n,"X",i,i*n)

Output

Enter number for its multiplication table

10

10 X 1 10

10 X 2 20

10 X 3 30

10 X 4 40

10 X 5 50

10 X 6 60

10 X 7 70

10 X 8 80

10 X 9 90

10 X 10 100

Ex. 12

Write a program to print 1+1/2+1/3+1/4+......... +1/N series.

Solution :

print("Enter value of N")

n=int(input())

sum=0

for i in range(1,n+1):

      sum=sum+1/i

print("The Sum is ",sum)

Output

Enter value of N

5

The Sum is 2.283333333333333

Ex. 13

Write a python program to check whether a given number is prime or not.

Solution :

# User can enter the value thru keyboard

print("Enter the number");

num = int(input())

# prime numbers are greater than 1

if num > 1:

# check for factors

for i in range(2,num):

     if (num % i) = = 0:

          print(num,"is not a prime number")

          break

    else:

          print(num,"is a prime number")

# if input number is less than

# or equal to 1, it is not prime

else:

     print(num,"is not a prime number")

Output

Enter the number

3

3 is a prime number

Ex. 14

Write a python program to find the prime numbers between given intervals.

Solution :

lower = int(input("Enter lower range: "))

upper = int(input("Enter upper range: "))

print("Prime numbers between", lower, "and",upper, "are:")

for num in range(lower,upper + 1):

prime numbers are greater than 1

if num > 1:

for i in range(2,num):

if (num % i) = = 0:

break

else:

print(num)

Output

Enter lower range: 1

Enter upper range: 10

Prime numbers between 1 and 10 are:

2

3

5

7

Ex. 15

Write a python program to display the star pattern as

*

**

***

****

*****

…

…

Users should enter the value of N

Solution :

print("Enter value of n")

n=int(input())

for i in range(0,n):

for j in range(0,i+1):

print('* ',end=""")

print("")

Output

Enter value of n

10

*

* *

* * *

* * * *

* * * * *

* * * * * *

* * * * * * *

* * * * * * * *

* * * * * * * * *

* * * * * * * * * *

Ex. 16

Write a python program to display the number pattern as follows

1 2 3 4 5

2 3 4 5

3 4 5

4 5

5

Solution:

for i in range (1,6):

for k in range(1,i):

print(end="")

for j in range(i,6):

print(" ",j,end="")

print();

Output

1 2 3 4 5

2 3 4 5

3 4 5

4 5

5

Write a python program to print the pattern as given below

A

A B

A B C

A B C D

A B C D E

Solution :

for i in range(1, 6):

     for j in range(65, 65+i):

         a = chr(j)

          print(a," ",end=""")

   print()

Output

A

A B

A B C

A B C D

A B C D E

Write a python program to print the pattern for alphabets

A A A A A

B B B B

C C C

D D

E

Solution :

num=65 #ASCII Value for A

for i in range(0,5):

for j in range(i,5):

ch=chr(num+i) # Converting ASCII to character

print(ch," ",end=""")

print();

Output

A A A A A

B B B B

C C C

D D

E

3. The break