Linklist.py

# -*- coding:utf-8 -*-

import Gamma

class Node(object):
    def __init__(self, val, p=0):
        self.docno = val[0]
        self.tf = val[1]
        self.next = p


class LinkList(object):
    def __init__(self):
        self.head = 0

    def __getitem__(self, key):

        if self.is_empty():
            print('linklist is empty.')
            return

        elif key < 0 or key > self.getlength():
            print('the given key is error')
            return

        else:
            return self.getitem(key)

    def __setitem__(self, key, value):

        if self.is_empty():
            print('linklist is empty.')
            return

        elif key < 0 or key > self.getlength():
            print('the given key is error')
            return

        else:
            self.delete(key)
            return self.insert(key)

    def initlist(self, data):

        self.head = Node(data[0])

        p = self.head

        for i in data[1:]:
            node = Node(i)
            p.next = node
            p = p.next

    def getlength(self):

        p = self.head
        length = 0
        while p != 0:
            length += 1
            p = p.next

        return length

    def is_empty(self):

        if self.getlength() == 0:
            return True
        else:
            return False

    def clear(self):

        self.head = 0

    def append(self, item):
        pre = self.head
        curr = self.head
        temp = item[0]
        if self.head == 0:
            self.head = Node(item)
            return
        else:
            val = curr.docno
            curr = curr.next
            while curr != 0:
                val += Gamma.__gammaUncompress__(curr.docno)
                pre = curr
                curr = curr.next
            # val += Gamma.__gammaUncompress__(curr.docno)
            item[0] = Gamma.__gamma__(temp - val)
            pre.next = Node(item)

    def getitem(self, index, double=False):

        if self.is_empty():
            print('Linklist is empty.')
            return
        j = 0
        p = self.head

        while p.next != 0 and j < index:
            p = p.next
            j += 1

        if j == index:
            if not double:
                return p.docno
            elif double:
                return p.docno, p.tf

        else:

            print ('target is not exist!')

    def insert(self, index, item):

        if self.is_empty() or index < 0 or index > self.getlength():
            print ('Linklist is empty.')
            return

        if index == 0:
            q = Node(item, self.head)

            self.head = q

        p = self.head
        post = self.head
        j = 0
        while p.next != 0 and j < index:
            post = p
            p = p.next
            j += 1

        if index == j:
            q = Node(item, p)
            post.next = q
            q.next = p

    def delete(self, index):

        if self.is_empty() or index < 0 or index > self.getlength():
            print('Linklist is empty. or Index Error')
            return

        if index == 0:
            self.head = self.head.next

        #        if index ==0:
        #           q = Node(item,self.head)

        #            self.head = q

        p = self.head
        post = self.head
        j = 0
        while p.next != 0 and j < index:
            post = p
            p = p.next
            j += 1

        if index == j:
            post.next = p.next

    def index(self, value):

        if self.is_empty():
            print('Linklist is empty.')
            return

        p = self.head
        i = 0
        while p.next != 0 and not p.docno == value:
            p = p.next
            i += 1

        if p.docno == value:
            return i
        else:
            return -1

    def increase(self, docno):
        if self.is_empty():
            # print('Linklist is empty.')
            return False
        p = self.head
        docno_val = p.docno
        while p.next != 0 and not docno_val == docno:   # 匹配docno
            p = p.next
            docno_val += Gamma.__gammaUncompress__(p.docno) # 解压？没懂
        if docno_val == docno:
            p.tf += 1   # 词项频率加一
            return True
        else:
            return False

    def output(self):
        p = self.head
        if p == 0:
            print('empty')
        s = ''
        count = p.docno
        s += str(count)+','+str(p.tf)+'|'
        p = p.next
        while p != 0:
            # print(count)
            count += Gamma.__gammaUncompress__(p.docno)
            s += str(count)+','+str(p.tf)+'|'
            p = p.next
        return s


#
# list_test = LinkList()
# data = [['a',1],['b',2],['c',1]]
# list_test.initlist(data)
# print(list_test.getitem(2,True))
# list_test.increase('c')
# print(list_test.getitem(2,True))
# list_test.append(['d',2])
# print(list_test.output())