Python Variables Passed as Parameters

immutable

• you get copies of values for parameters (pass-by-value)
• the variable has not been changed
• these are primitive types
• examples: integer, float, Boolean, string

mutable

• these variables act like they have a URL that is being copied (pass-by-reference)
• you get reference (the URL) for parameters
• they are changed in place when you assign
• non-primitive types
• examples: canvas, pixel, SimpleImage, list