| 标题 | python列表操作实例 |
| 范文 | 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 希望本文所述对大家的Python程序设计有所帮助。 |
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