Write a function in to search and display details of all trains, whose destination is Delhi from a binary file TRAIN.DAT.

Q. Write a function in to search and display details of all trains, whose destination is Delhi from a binary file TRAIN.DAT. Assuming the binary file is containing the objects of the following dictionary type:

Train = { 'Tno': ___ , 'From': ____ , 'To' : ____}

You can understand by Watching video :-

Answer :-

import pickle

def search() :
      file = open("TRAIN.DAT","rb")
      found = 0
      try :
            while True :
                  Train = pickle.load(file)
                  if Train [ "To" ] == 'Delhi':
                        print(Train)
                        found=1
            
      except EOFError :
            if found == 0:
                  print("Not found !!!")     
      file.close()

search()

Program for writing in the binary file :-

import pickle
f = open("TRAIN.DAT","wb")

while True :
    Tno = int(input("Enter Train number ( -1 for exit ) :- "))
    if Tno == -1 :
        break
    From = input("Enter Station name :- ")
    To = input("Enter Station name where that train will go:- ")
    Train = { 'Tno': Tno , 'From': From , 'To' : To }
    pickle.dump( Train , f)
print("Your file is ready.")
f.close()

The output of the above program :-

Enter Train number ( -1 for exit ) :- 456365
Enter Station name :- Kota
Enter the Station name where that train will go:- Mub
Enter Train number ( -1 for exit ) :- 53764
Enter Station name :- Kota
Enter the Station name where that train will go:- Delhi
Enter Train number ( -1 for exit ) :- 45343
Enter Station name :- Pray
Enter the Station name where that train will go:- JK
Enter Train number ( -1 for exit ) :- 34356
Enter Station name :- Delhi
Enter the Station name where that train will go:- Mub
Enter Train number ( -1 for exit ) :- 93641
Enter Station name :- JK
Enter the Station name where that train will go:- Delhi
Enter Train number ( -1 for exit ) :- 63444
Enter Station name :- Mub
Enter the Station name where that train will go:- Delhi
Enter Train number ( -1 for exit ) :- -1
Your file is ready.
>>> 

The output of Main progarm :- 

{'Tno': 53764, 'From': 'Kota', 'To': 'Delhi'}
{'Tno': 93641, 'From': 'JK', 'To': 'Delhi'}
{'Tno': 63444, 'From': 'Mub', 'To': 'Delhi'}
>>>