Goal:

I want to create a series of tutorials teaching people how to use vim editor, which I think is the best editor in the world. So for this part of the tutorial, I want to introduce the basic cursor movements in vim, Up(k), Down(j), Left(h), Right(l).

Code Demo:

To Start With

I need to capture the key press on the screen. My first instinct was to use the function input(). However, after gave it a try, I know that wasn’t the right solution.

k = input()

while k != "q" :
    if k == "j":
        # move the turtle...
    if ...

    k = input()

Searching Solution

I googled on How to move turtle using keypress and found the solution. https://www.youtube.com/watch?v=WunZOSRM-vA&ab_channel=pyGuru.

def f():
    t.fd(10)

def b():
    t.bd(10)

def l():
    t.left(10)

def r():
    t.right(10)

Setbacks

It uses fd, bd, right, left to move the turtle. However, what I was hoping for is that the turtle will only move Up, Down, Left and Right. Turning directions is not what I was looking for.

lightbule Moment

I vaguely remember a function that can move the turtle to a specific position. So I was thinking if I can get the current position of the turtle and add certain value to the x or y coordinate, this way I can get exactly what I was expecting, completely ignoring the rotation part.

Here is the revised code

def f():
  x, y = t.pos()
  t.setpos(x, y+10)
def b():
  x, y = t.pos()
  t.setpos(x, y-10)
  
def l():
  x, y = t.pos()
  t.setpos(x-10, y)

def r():
  x, y = t.pos()
  t.setpos(x+10, y)

Now it’s working as I intended, I also added a new function to clean the screen and let the user do more practice.

 def c():
  t.clear()

Next Move

My next step would be to make several mazes with different levels of difficulty to help the user practice cursor movement and eventually build their muscle memory.