PYTHON: The Vacuuminator needs to figure out how far it needs to travel to reach the nearest wall.

Write a function distance$\_$to$\_$wall$($world$).$ This function should return an integer representing the smallest number of moves the Vacuuminator can make before hitting a wall.

If there are no walls present in the world, your function should return None.

Hint: Think about how you can calculate the number of moves the Vacuuminator can make before hitting a wall by using the number of rows and columns between the Vacuuminator and the wall. Also see the lecture recording on $25/3/2024$ for some more guidance if you are having trouble. $>>>$ distance$\_$to$\_$wall$([[\text{'}$D$\text{'},\text{'}$W$\text{'}],[\text{'}$X$\text{'},\text{'}$E$\text{'}]])$

$2$

$>>>$ distance$\_$to$\_$wall$([[\text{'}$W$\text{'},\text{'}$E$\text{'}],[\text{'}$X$\text{'},\text{'}$E$\text{'}]])$

$1$

$>>>$ distance$\_$to$\_$wall$([[\text{'}$D$\text{'},\text{'}$D$\text{'}],[\text{'}$D$\text{'},\text{'}$D$\text{'}],[\text{'}$W$\text{'},\text{'}$W$\text{'}],[\text{'}$D$\text{'},\text{'}$E$\text{'}],[\text{'}$W$\text{'},\text{'}$E$\text{'}],[\text{'}$E$\text{'},\text{'}$D$\text{'}],[\text{'}$E$\text{'},\text{'}$X$\text{'}]])$

$3$