Why is the result getting converted to str?

Question

elif user_input == "add":
num1 = float(input("Enter a number: "))
num2 = float(input("Enter another number: "))
result = str(num1 + num2)
print("The answer is " + result)

Answer 1

num1 = 1.2
num2 = 3.4
print( num1 +num2 ) # ok

print("" + num1 + num2) # TypeError: Can't convert 'float' object to str implicitly.

str(float_object) is EXPLICIT and Python is happy.

Answer 2

Removed my last comment to avoid any miss-understanding.

If he/she wanted to print them together without having cast it to a string they could have separated it with a comma.
print("my str", result)

I suppose he/she tried the + and got an error so just converted it to avoid the error, even though the casting was not necessary