ERROR PRACTICE
WHAT TO LOOK FOR:
A) A local or global name could not be found
*Check to make sure you have defined all variables before they are used.
B) Your code is not legal Jython.
*Look for syntax errors, like indentations, missing parentheses and colons, and equal
signs that are either needed or unneeded (if statements and setting variables, = vs.
==).
C) An attempt was made to call a function with a parameter of an invalid type.
*Remember what needs to be input into each function.
pickAFile()
makePicture(picture)
getRed(pixel)
setRed(pixel, redamount)
getColor(pixel)
setColor(pixel, color)
return picture
distance(color, color)
makeColor(red, green, blue)
D) It’s a logical error. (It runs but doesn’t do what you intended it to do)
*Common ones are returns inside a loop, no returns, prints instead of returns; trace
to see what the function does.
E) It’s an out-of-bounds error.
*Does the range start with 0 for a pixel? Pixels start at 1,1. Are the numbers too big
for the picture or canvas? Then it would have no pixel there.
