Faces, Debugging, Lists, Mutation, Objects

1.6-1.10 3.1-3.5 9.9 10.6, 10.8, 10.10-10.13

syntax

structure of a program and rules abt the structure

Who or what typically finds syntax errors

compiler / interpreter

Who or what typically finds runtime errors

interpreter

runtime error

error does not appear until you run the program

semantic error

program will run but not deliver the correct result

important part of debugging

boundary conditions

what does strings are immutable mean

cannot change an existing string

what operator concatenates a list

+

lists are mutable means

change an item in a list by accessing it directly as part of the assignment statement using an []

how to insert elements in a list

• squeezing them into an empty slice at the desired location

ex:

alist = ['a', 'd', 'f']

alist[1:1] = ['b', 'c']

print(alist)

alist[4:4] = ['e']

print(alist)

['a', 'b', 'c', 'd', 'f']
['a', 'b', 'c', 'd', 'e', 'f']

what does the is operator do

• test whether two names refer to the same object

• is operator will return true if the two references are to the same object

what is a list

collection of references to objects

aliased

same list has two different names