Solution Exercise 109: python code to create dictionary with 1 , 2 , 3, ... as keys and their sums as values

Exercise 109

Write a program in Python that asks the user to enter an integer n and return a dictionary whose keys are the integers 1, 2, 3, ... n and whose values ​​are the sums 1, 1+ 2, 1 + 2 + 3,... 1 + 2 + 3 + ... + n.

Solution

# create a function which calculates the sum 1 + 2 + 3 + ... + n
def sumInt(n):
    s = 0
    for i in range(1, n + 1):
        s = s + i
    return s

# create an empty dictionary which will contains the key 1 , 2 , 3 , ... , n and their values 
d= dict({})
n = int(input("Enter value of integer n"))
for i in range(1, n):
    d[i] = sumInt(i)
    
# display obtained  dictionary d
print("The obtained dictionary is d = " , d)
# The output is : 
#The obtained dictionary is d =  {1: 1, 2: 3, 3: 6, 4: 10, 5: 15, 6: 21}