Print Natural Numbers Summation Pattern in Python

When it is required to read a number and print the pattern of summation of natural numbers, a simple ‘for’ loop can be used.

Below is a demonstration of the same −

Example

 Live Demo

my_num = int(input("Enter a number... "))
for j in range(1,my_num+1):
   my_list=[]
   for i in range(1,j+1):
      print(i,sep=" ",end=" ")
      if(i<j):
         print("+",sep=" ",end=" ")
      my_list.append(i)
   print("=",sum(my_list))

print()

Output

Enter a number... 5
1 = 1
1 + 2 = 3
1 + 2 + 3 = 6
1 + 2 + 3 + 4 = 10
1 + 2 + 3 + 4 + 5 = 15

Explanation

• A number is taken as input from the user.

• This number is iterated over.

• An empty list is defined.

• Another ‘for’ loop is initiated.

• The separator is specified as ‘’.

• If the value of inner iterator is less than value of outer iterator, the ‘+’ is used.

• These values are appended to the empty list.

• Their sum is computed and displayed as the output.