In [1]:

    

class Pair:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def __repr__(self):
        return 'Pair({0.x!r}, {0.y!r})'.format(self)
    def __str__(self):
        return '({0.x!s}, {0.y!s})'.format(self)


    

In [3]:

    

p = Pair(3,4)


    

In [4]:

    

print('p is {0}'.format(p))


    

    




p is (3, 4)

In [5]:

    

class PairX:
    def __init__(self, x, y):
        self.x = x
        self.y = y


    

In [6]:

    

pX = PairX(3,4)


    

In [7]:

    

print('p is {0}'.format(pX))


    

    




p is <__main__.PairX object at 0x000001F91AE8B160>

In [8]:

    

_formats = {
    'ymd' : '{d.year}-{d.month}-{d.day}',
    'mdy' : '{d.month}/{d.day}/{d.year}',
    'dmy' : '{d.day}/{d.month}/{d.year}'
    }

class Date:
    def __init__(self, year, month, day):
        self.year = year
        self.month = month
        self.day = day

    def __format__(self, code):
        if code == '':
            code = 'ymd'
        fmt = _formats[code]
        return fmt.format(d=self)


    

In [9]:

    

d = Date(2012, 12, 21)


    

In [10]:

    

format(d)


    

    
Out[10]:





'2012-12-21'

In [1]:

    

#Create a linked list.

class Node:
    def __init__(self, cargo=None, next=None):
        self.cargo = cargo
        self.next  = next

    def __str__(self):
        return str(self.cargo)


    

In [2]:

    

n1 = Node(1)
n2 = Node(2)
n3 = Node(3)


    

In [4]:

    

n1.next = n2
n2.next = n3


    

In [6]:

    

print(n1.next)


    

    




2

In [9]:

    

def printList(node):
    while node:
        print (node)
        node = node.next


    

In [11]:

    

printList(n1)


    

    




1
2
3

In [18]:

    

def removeSecond(list):
    if list == None: return
    first = list
    second = list.next
    # make the first node refer to the third
    first.next = second.next
    # separate the second node from the rest of the list
    second.next = None
    return second


    

In [19]:

    

removed = removeSecond(n1)


    

In [21]:

    

print(removed)


    

    




2

In [24]:

    

printList(n1)


    

    




1
3

In [ ]: