Hardware Reference
In-Depth Information
4.
Finally, press the Enter key on the keyboard twice, and the Python Shell recog-
nises that you have finished typing in indented statements.
5.
Now ask the Python Shell to run this function by typing in its name with brack-
ets after it:
myname()
6.
Try typing
myname()
a few more times and see what happens.
At first it might seem a little strange that you typed instructions into the Python Shell
but nothing happened. Normally when you type at the Python Shell, things happen as
soon as you press the Enter key, so why didn't it work this time? This time, you did
something different, however: you “defined” a new function called
myname
and asked
Python to remember the three
print
statements as belonging to that function.
Python has stored those
print
statements in the computer memory, rather than run-
ning them straight away. Now, whenever you type
myname()
it runs those stored
statements, and you get your three lines of text printed on the screen.
Functions are very powerful, and allow you to associate any number of Python pro-
gram statements to a simple name, a little bit like a mini-program. Whenever you want
those program statements to run, you just type the name of the function.
Let's put this to good use by defining a function that draws your house. Then, when-
ever you want a house made from cobblestone, all you have to do is type
House()
and
it is built automatically for you!
1.
So that you don't break your already working
buildHouse.py
, choose
File
➪
Save As from the editor menu, and call the new file
buildHouse2.py
.
2.
At the top of the program after the
import
statements, define a new function
called
house
:
def house():
3.
Now move the
midx
,
midy
, and all of your
setBlocks()
statements so that
they are indented under the
def house():
line. Here is what your program
should now look like. Be careful to get the indents correct:
import mcpi.minecraft as minecraft
import mcpi.block as block
mc = minecraft.Minecraft.create()
SIZE = 20
def house():
midx = x + SIZE/2
midy = y + SIZE/2
