Question

PYTHON. Continues off another code(other code is below). I don't understand this. Someone please help! Comment the lines please so I can understand.

There are short and med files lengths for each the list of names/ids and then search id file. These are the input files:

https://codeshare.io/aVQd46
https://codeshare.io/5M3XnR
https://codeshare.io/2W684E
https://codeshare.io/5RJwZ4

LinkedList ADT to store student records(code is below). Using LinkedList ADT instead of the Python List. You will need to use the Student ADT(code is below)

1. Imports the Student class
2. Imports the time module
3. Imports the myLinkedList class

1. Create a main() function which:
   1. Open the list of names files and read the student information and puts them into a list of Student's. You will need to use the strip() function on the line of input from the file to remove extra white space, then use split() using a tab as a deliminator to split the line of input into the student ID and name. The ID should also be converted to an integer so that it can more easily be compared with other IDs.
   2. Close the 1st file
   3. Open the search file and read each line of the 2nd file and create a new Student record (except that it will have only an ID and not a name). Search for a match in the list of Student's and print the record that matches. If there is no match, then print an appropriate message. You created a function the the myLinkedList class that should help with this.
   4. An sample output might looks something like this:
      
      Found student record: 7654321 (Ashley Tomkin)
      Found student record: 2345678 (Katie Smith)
      Student ID: 1234567 not found
      Found student record: 3456789 (Matt Simpson)
      Student ID 9876543 not found
2. You should first work with the short versions of the input file before moving on to the medium versions. After your program is successfully capable to adding all of the students to the Linked List and is able to read the student IDs in the search file and print an appropriate message, then you want to time how long it takes.  
   1. First, comment out the printing of the messages, so that you aren't timing that.  
   2. Surround the section of code you want to time with two time stamps (calls to the time.time()method. The elapse time can be calculated by taking the difference between the two time stamps. For example:
           startTime = time.time()
           # Do the stuff you want to time
      
           endTime = time.time()
           print("Time to do " + format(endTime - startTime, "6.4f") + " seconds.")
   1. Time how long it takes to insert the student records into the Linked List as well as search for them using the medium versions of the files. For example, you might something like this:
      
      The time to insert 10000 student records into a Linked List = 0.0341 seconds.
      The time to search 10000 student records from a Linked List = 23.9849 seconds.

LinkedList ADT:

class myLinkedList:
    def __init__(self):
        self.__head = None
        self.__tail = None
        self.__size = 0

    def insert(self, i, data):
        if self.isEmpty():
            self.__head = listNode(data)
            self.__tail = self.__head
        elif i <= 0:
            self.__head = listNode(data, self.__head)
        elif i >= self.__size:
            self.__tail.setNext(listNode(data))
            self.__tail = self.__tail.getNext()
        else:
            current = self.__getIthNode(i - 1)
            current.setNext(listNode(data, current.getNext()))
            if current == self.__tail:
                self.__tail = self.__tail.getNext()
        self.__size += 1

    def __getIthNode(self, i):
        current = self.__head
        count = 0
        while current is not None and count < i:
            count = count + 1
            current = current.getNext()
        return current

    def __str__(self):
        current = self.__head
        result = ""
        while current is not None:
            result = result + " " + str(current.getData())
            current = current.getNext()
        return result

    #returns True if list is empty, else False
    def isEmpty(self):
        return self.__head==None

    #returns the length
    def __len__(self):
        '''count = 0
        current=self.__head
        #counting number of nodes
        while current is not None:
            count = count + 1
            current = current.getNext()
        #returning count
        return count'''
        return self.__size

    #adds to the front
    def prepend(self, item):
        #adding the item at index 0
        self.insert(0,item)

    #adds to the rear
    def append(self,item):
        #adding the item at the end
        self.insert(len(self),item)

    #removes and returns the element at index i
    def pop(self, i):
        #validating index
        if i<0 or i>=len(self):
            return None #invalid index
        #finding ith node
        node=self.__getIthNode(i)
        #if it is head, updating head node
        if node==self.__head:
            self.__head=self.__head.getNext()
            self.__size-=1
            return node.getData() #returning removed data
        #finding previous node
        prev=self.__getIthNode(i-1)
        #linking node at i+1 as next node of node at i-1
        prev.setNext(node.getNext())
        self.__size -= 1
        return node.getData() #returning removed data

    #helps to access data by index (using [])
    def __getitem__(self, index):
        #returning data of node at index
        return self.__getIthNode(index).getData()

    #helps to set data by index (using [])
    def __setitem__(self, index, value):
        #updates the data of node at index
        self.__getIthNode(index).setData(value)

    #returns the index of an item, if exists
    def find(self,item):
        #looping and comparing each item with target
        for i in range(len(self)):
            if self.__getitem__(i)==item:
                #found
                return i
        return -1 #not found

student class ADT:

class Student:
def __init__(self, id=None, name=""):
self.id = id
self.name = name

def getID(self):
return self.id

def getName(self):
return self.name

def setID(self, id):
self.id = id

def setName(self, name):
self.name = name

def __str__(self):
#print out
print(str(self.id) + "(" + self.name+")")

def __cmp__(self,other_id):
ot_id = other_id.getID()
if (self.id < ot_id):
p = -1
elif (self.id > ot_id):
p = 1
elif (self.id == ot_id):
p = 0
return p

def __eq__(self,other_id):
x = self.__cmp__(other_id)
if x == 0:
print(True)
else:
print(False)

def __ne__(self,other_id):
x = self.__cmp__(other_id)
if x == 0:
print(False)
else:
print(True)

def __lt__(self,other_id):
x = self.__cmp__(other_id)
if x == -1:
print(True)
else:
print(False)

def __le__(self,other_id):
x = self.__cmp__(other_id)
if x == 0 or x==-1:
print(True)
else:
print(False)

def __gt__(self,other_id):
k = self.__cmp__(other_id)
if (k == 1):
print(True)
else:
print(False)

def __ge__(self,other_id):
k = self.__cmp__(other_id)
if (k == 0 or k==1):
print(True)
else:

print(False)

Answer 1

#I have made two corrections to you ADT LinkedList those are

#You haven't given listNode() implementation so I implemented it.

class listNode(object):
def __init__(self, data=None, next_node=None):
self.data = data
self.next_node = next_node

def getNext(self):
return self.next_node

def getData(self):
return self.data

#Second one I just rename the method __getIthNode in LinkedList to __getIthNode__.

#CODE

from ADT import Student,myLinkedList
import time
def main():
   Students=myLinkedList()#Creating Students LL(Linked List)
   startTime=time.time()#Starting the time
   fp=open("mediumData.txt","r")#opening file in readMode
   for line in fp.readlines():
       line=line.strip()
       idNumber,Name=line.split("\t")
       idNumber=int(idNumber)#Convert id to integer
       std=Student(idNumber,Name)#Creating Student Object
       Students.prepend(std)#Adding each student to the head of the LL
   #Closing the file
   fp.close()
   #Finise the time
   endTime=time.time()
   print("Time to Insert "+ str(len(Students)) + "student records Into a Linked List = "+ format(endTime - startTime, "6.4f") + " seconds.")
  
   startTime=time.time()
   #Opening the search File
   fp=open("mediumSearch.txt","r")
   count=0
   for searchID in fp.readlines():
       count+=1
       searchID=int(searchID)
       temp=Students.__getIthNode__(0)
       while(temp):
           if(temp.data.getID()==searchID):
               print("Found student record:",searchID,"("+temp.data.getName()+")")
               break
           temp=temp.getNext()
       else:
           print("Student ID:", searchID, "not found")
   fp.close()
   endTime=time.time()
   print("Time time to search",count,"student records from a Linked List = "+format(endTime - startTime, "6.4f") + " seconds.")
main()

#The ADT.py File

class myLinkedList:
def __init__(self):
self.__head = None
self.__tail = None
self.__size = 0
def __getIthNode__(self, i):
current = self.__head
count = 0
while current is not None and count < i:
count = count + 1
current = current.getNext()
return current

def insert(self, i, data):
if self.isEmpty():
self.__head = listNode(data)
self.__tail = self.__head
elif i <= 0:
self.__head = listNode(data, self.__head)
elif i >= self.__size:
self.__tail.setNext(listNode(data))
self.__tail = self.__tail.getNext()
else:
current = self.__getIthNode__(i - 1)
current.setNext(listNode(data, current.getNext()))
if current == self.__tail:
self.__tail = self.__tail.getNext()
self.__size += 1

#getIthNode
  

def __str__(self):
current = self.__head
result = ""
while current is not None:
result = result + " " + str(current.getData())
current = current.getNext()
return result

#returns True if list is empty, else False
def isEmpty(self):
return self.__head==None

#returns the length
def __len__(self):
'''count = 0
current=self.__head
#counting number of nodes
while current is not None:
count = count + 1
current = current.getNext()
#returning count
return count'''
return self.__size

#adds to the front
def prepend(self, item):
#adding the item at index 0
self.insert(0,item)

#adds to the rear
def append(self,item):
#adding the item at the end
self.insert(len(self),item)

#removes and returns the element at index i
def pop(self, i):
#validating index
if i<0 or i>=len(self):
return None #invalid index
#finding ith node
node=self.__getIthNode__(i)
#if it is head, updating head node
if node==self.__head:
self.__head=self.__head.getNext()
self.__size-=1
return node.getData() #returning removed data
#finding previous node
prev=self.__getIthNode__(i-1)
#linking node at i+1 as next node of node at i-1
prev.setNext(node.getNext())
self.__size -= 1
return node.getData() #returning removed data

#helps to access data by index (using [])
def __getitem__(self, index):
#returning data of node at index
return self.__getIthNode__(index).getData()

#helps to set data by index (using [])
def __setitem__(self, index, value):
#updates the data of node at index
self.__getIthNode__(index).setData(value)

#returns the index of an item, if exists
def find(self,item):
#looping and comparing each item with target
for i in range(len(self)):
if self.__getitem__(i)==item:
#found
return i
return -1 #not found

class listNode(object):
def __init__(self, data=None, next_node=None):
self.data = data
self.next_node = next_node

def getNext(self):
return self.next_node

def getData(self):
return self.data

class Student:
def __init__(self, id=None, name=""):
self.id = id
self.name = name

def getID(self):
return self.id

def getName(self):
return self.name

def setID(self, id):
self.id = id

def setName(self, name):
self.name = name

def __str__(self):
#print out
print(str(self.id) + "(" + self.name+")")

def __cmp__(self,other_id):
ot_id = other_id.getID()
if (self.id < ot_id):
p = -1
elif (self.id > ot_id):
p = 1
elif (self.id == ot_id):
p = 0
return p

def __eq__(self,other_id):
x = self.__cmp__(other_id)
if x == 0:
print(True)
else:
print(False)

def __ne__(self,other_id):
x = self.__cmp__(other_id)
if x == 0:
print(False)
else:
print(True)

def __lt__(self,other_id):
x = self.__cmp__(other_id)
if x == -1:
print(True)
else:
print(False)

def __le__(self,other_id):
x = self.__cmp__(other_id)
if x == 0 or x==-1:
print(True)
else:
print(False)

def __gt__(self,other_id):
k = self.__cmp__(other_id)
if (k == 1):
print(True)
else:
print(False)

def __ge__(self,other_id):
k = self.__cmp__(other_id)
if (k == 0 or k==1):
print(True)
else:
print(False)

#OUTPUTS