Answer:
In Python
def sum(num):
total = 0
for i in range(1,num+1):
total = total + i
print(total)
i = int(input("User input [1 - 1000]: "))
if i >= 1 and i <= 1000:
sum(i)
else:
print("Invalid User Input")
Explanation:
The function is declared here
def sum(num):
The sum is initialized to 0
total = 0
The following iteration calculates sum from 1 to the user input
for i in range(1,num+1):
total = total + i
The total is then printed
print(total)
The main begins here
This line prompts user for input
i = int(input("User input [1 - 1000]: "))
The following if condition ensures that user input is between 1 and 1000
if i >= 1 and i <= 1000:
sum(i)
else:
print("Invalid User Input")