Hello, please help me with my Python homework! Just getting a couple of errors. Cheers.

Here's my code:

def pop(self):

"""

-------------------------------------------------------

Pops and returns the top of stack. The data element is

removed from the stack. Attempting to pop from an empty

stack throws an exception.

Use: value = stack.pop()

-------------------------------------------------------

Returns:

value - the value at the top of stack (?)

-------------------------------------------------------

"""

assert not self.isEmpty(), "Cannot pop from an empty stack"

value = deepcopy( self._values[ self._top ] )

self._top -=1

return value

def peek(self):

"""

-------------------------------------------------------

Returns a copy of the value at the top of the stack without

removing it.

Attempting to peek at an empty stack throws an exception.

Use: value = stack.peek()

-------------------------------------------------------

Returns:

value - a copy of the value at the top of stack (?)

-------------------------------------------------------

"""

#your code goes here

assert len(self.values) > 0, "Cannot peak at an empty stack"

value = deepcopy(self.values[-1])

return value

Test for assertion fails: 'peek' ERROR: 'Stack' object has no attribute 'values' Test 'peek' with various values: '[99]' ERROR: 'Stack' object has no attribute 'values' Test 'peek' with various values: '[11, 22, 33, 44, 55, 66]' ERROR: 'Stack' object has no attribute 'values' Test 'pop' with various values: '[99]' ERROR: Remaining stack incorrect Test 'pop' with various values: '[1,1,1, 1, 1, 1]' ERROR: Remaining stack incorrect