Below is a simple **python **program to calculate sum of two numbers:

# __Function to calculate the sum of two numbers__

def sum_of_two_numbers(num1, num2):

return num1 + num2

# Input

num1 = float(input("Enter the first number: "))

num2 = float(input("Enter the second number: "))

# Calculate the sum

result = sum_of_two_numbers(num1, num2)

# Output

print("The sum of", num1, "and", num2, "is:", result)

```

__In this program:__

- We define a function `sum_of_two_numbers` that takes two parameters `num1` and `num2` and returns their sum.

- We prompt the user to input two numbers using the `input()` function and convert them to floating-point numbers using `float()`.

- We calculate the sum of the two numbers by calling the `sum_of_two_numbers` function with the input numbers as arguments.

- Finally, we print the sum using the `print()` function.

You can run this program in any Python environment, such as IDLE, Jupyter Notebook, or command line, and it will prompt you to enter two numbers. After entering the numbers, it will display the sum of those numbers.