Question

NextStep is an organization which has a pool of resource persons to conduct training workshops on various topics related to ICT. The data of all its Resource Persons is stored in a binary file RESOURCES.DAT using the following record structure (each record is a tuple):
        (R_ID, R_Name, R_Expertise, Charges)
where:

R_ID	– Resource Person’s ID (An integer)
R_Name	– Resource Person’s Name (A string)
R_Expertise	– Area of expertise of the Resource Person
Charges	– Charges (in rupees) per hour to conduct a workshop

 For example, a record in the file is:
(12, ‘P. Velusami’, ‘Machine Learning’, 5000)

In this context, write the following user defined functions in Python:

1. Append() – To input the data of a Resource Person and write it in the file RESOURCES.DAT.
2. Update() – To increase the Charges of each resource person by 500.

Answer 1

1. import pickle
   
   def Append():
       fobj = open('RESOURCES.DAT', 'ab')
       r_id = int(input('Enter RID: '))
       r_name = input('Enter Name: ')
       r_exp = input('Enter Expertise: ')
       charges = float(input('Enter Charges: '))
       
       # Store data as a tuple
       rec = (r_id, r_name, r_exp, charges)
       pickle.dump(rec, fobj)
       fobj.close()

2. def Update():
       fobj = open('RESOURCES.DAT', 'rb+')
       try:
           while True:
               pos = fobj.tell()           # Save current pointer position
               rec = list(pickle.load(fobj)) # Convert tuple to list to edit
               rec[3] += 500               # Increase Charges (index 3) by 500
               
               fobj.seek(pos)              # Move pointer back to record start
               pickle.dump(tuple(rec), fobj) # Save as tuple
       except EOFError:
           fobj.close()