First Three Spaces

This question involves finding spaces in a string. In a file spaces. py$,$ write a program that reports the first three occurrence of a space, using a while loop:

Enter a string: This is the user's input

There's a space in position $4.$

There's a space in position $7.$

There's a space in position $11.$

Make sure your program behaves correctly and doesn't give an error if there are less than three spaces in the string $($but otherwise behaves the same$).$

Enter a string: This is the

There's a space in position $4.$

There's a space in position $7.$