input() function allows dynamic interaction with the program. This input can then be used to call specific functions based on the user's choice .

Let’s take a simple example to call function based on user's input .

Example:

def add(x, y):
    return x + y  # Add

def sub(x, y):
    return x - y  # Subtract

a = input()  # Input
if a == "add":
    res = add(5, 3)  
elif a == "sub":
    res = sub(5, 3)
else:
    res = "Invalid operation"  # Error

print("Result:", res)  

def add(x, y):

    return x + y  # Add

​

def sub(x, y):

    return x - y  # Subtract

​

a = input()  # Input

if a == "add":

    res = add(5, 3)  

elif a == "sub":

    res = sub(5, 3)

else:

    res = "Invalid operation"  # Error

​

print("Result:", res)

Explanation:

• This code takes user input to determine the desired operation .
• Based on the input, the corresponding function is called.
• It outputs the result of the operation or an error message if the input is invalid.

Using Dictionary for Function Mapping

Instead of using if statements, we can use a dictionary to map user inputs to function calls.

def multiply(x, y):
    return x * y  # Multiply
def divide(x, y):
    return x / y  # Divide
fun = {
    "mul": multiply,
    "div": divide
}
a = input()  # Input
if a in fun:
    result = fun[a](6, 3)  # Call
else:
    result = "Invalid operation"  # Error
print("Result:", result)  # Output

def multiply(x, y):

    return x * y  # Multiply

def divide(x, y):

    return x / y  # Divide

fun = {

    "mul": multiply,

    "div": divide

}

a = input()  # Input

if a in fun:

    result = fun[a](6, 3)  # Call

else:

    result = "Invalid operation"  # Error

print("Result:", result)  # Output

Explanation:

• This code perform respective operations.
• Maps input to functions.
• It calls the function based on input .