how to understand when to use stack in puthon code example

Example 1: stack in python

# Stack
class My_stack():
    def __init__(self):
        self.data = []
    def my_push(self, x):
        return (self.data.append(x))
    def my_pop(self):
        return (self.data.pop())
    def my_peak(self):
        return (self.data[-1])
    def my_contains(self, x):
        return (self.data.count(x))
    def my_show_all(self):
        return (self.data)

arrStack = My_stack()     
arrStack.my_push(1)
arrStack.my_push(2)
arrStack.my_push(1)
arrStack.my_push(3)
print(arrStack.my_show_all())
arrStack.my_pop()
print(arrStack.my_show_all())
print(arrStack.my_contains(1))

Example 2: stack example in python

>>> myStack = []

>>> myStack.append('a')
>>> myStack.append('b')
>>> myStack.append('c')

>>> myStack
['a', 'b', 'c']

>>> myStack.pop()
'c'
>>> myStack.pop()
'b'
>>> myStack.pop()
'a'

>>> myStack.pop()
Traceback (most recent call last):
  File "<console>", line 1, in <module>
IndexError: pop from empty list