本文实例讲述了python列表操作的方法。分享给大家供大家参考。

具体实现方法如下：

复制代码 代码如下:class Node:

"""Single node in a data structure"""

def __init__(self, data):

"""Node constructor"""

self._data = data

self._nextNode = None

def __str__(self):

"""Node data representation"""

return str(self._data)

class List:

"""Linked list"""

def __init__(self):

"""List constructor"""

self._firstNode = None

self._lastNode = None

def __str__(self):

"""List string representation"""

if self.isEmpty():

return "empty"

currentNode = self._firstNode

output = []

while currentNode is not None:

output.append(str(currentNode._data))

currentNode = currentNode._nextNode

return " ".join(output)

def insertAtFront(self, value):

"""Insert node at front of list"""

newNode = Node(value)

if self.isEmpty(): # List is empty

self._firstNode = self._lastNode = newNode

else: # List is not empty

newNode._nextNode = self._firstNode

self._firstNode = newNode

def insertAtBack(self, value):

"""Insert node at back of list"""

newNode = Node(value)

if self.isEmpty(): # List is empty

self._firstNode = self._lastNode = newNode

else: # List is not empty

self._lastNode._nextNode = newNode

self._lastNode = newNode

def removeFromFront(self):

"""Delete node from front of list"""

if self.isEmpty(): # raise exception on empty list

raise IndexError, "remove from empty list"

tempNode = self._firstNode

if self._firstNode is self._lastNode: # one node in list

self._firstNode = self._lastNode = None

else:

self._firstNode = self._firstNode._nextNode

return tempNode

def removeFromBack(self):

"""Delete node from back of list"""

if self.isEmpty(): # raise exception on empty list

raise IndexError, "remove from empty list"

tempNode = self._lastNode

if self._firstNode is self._lastNode: # one node in list

self._firstNode = self._lastNode = None

else:

currentNode = self._firstNode

# locate second-to-last node

while currentNode._nextNode is not self._lastNode:

currentNode = currentNode._nextNode

currentNode._nextNode = None

self._lastNode = currentNode

return tempNode

def isEmpty(self):

"""Returns true if List is empty"""

return self._firstNode is None

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