Answer 1

I done all of them except 3 and 7

class Stack:

def __init__(self, list):
self.stack = list

# stack methods

def push(self, item):
self.stack.append(item)

def pop(self):
if not self.isEmpty():
self.stack.pop(-1)

else:
return None

def peek(self):
if not self.isEmpty():
return self.stack[-1]

else:
return None

def size(self):
return len(self.stack)

def isEmpty(self):
return self.stack == []

# special method(s)

def __len__(self):
return len(self.stack)