Create a simple calculator which can perform basic arithmetic operations like addition, subtraction, multiplication or division depending upon the user input.

Here is a simple Python program to make a basic calculator that can perform addition, subtraction, multiplication, and division: 

# define a function for addition
def add(x, y):
    return x + y

# define a function for subtraction
def subtract(x, y):
    return x - y

# define a function for multiplication
def multiply(x, y):
    return x * y

# define a function for division
def divide(x, y):
    return x / y

# take user input for operation choice
print("Select operation.")
print("1. Add")
print("2. Subtract")
print("3. Multiply")
print("4. Divide")

choice = input("Enter choice (1/2/3/4): ")

# take user input for numbers
num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

# perform operation based on user choice
if choice == '1':
    print(num1, "+", num2, "=", add(num1,num2))

elif choice == '2':
    print(num1, "-", num2, "=", subtract(num1,num2))

elif choice == '3':
    print(num1, "*", num2, "=", multiply(num1,num2))

elif choice == '4':
    print(num1, "/", num2, "=", divide(num1,num2))

else:
    print("Invalid input")

In this program, we define four functions for addition, subtraction, multiplication, and division respectively. Then, we take user input for the operation choice and the two numbers to perform the operation on. Finally, based on the user choice, we call the appropriate function to perform the operation and display the result.