def reverse_string(string):
string_stack = Stack()
reversed_string = ''
for i in range(len(string)):
string_stack.append(string[i])
for i in range(len(string)):
reversed_string += string_stack.read()
string_stack.remove()
return reversed_string
def pathto(self, v):
"""Return the paths to a vertex"""
if not self.connected(v): return None
path = Stack()
while v != self.source:
path.push(v)
v = self.edgeto[v]
path.push(v)
return path
