Delete record in binary file python

Write a python program to delete student data from binary file with Practical Example

Program Description:

This program to read binary file and delete student record from it

Program Logic:

• Include pickle module in the program by using import statement
• Enter roll number of student using the input() function and store it in a variable say ‘roll’
• Open binary file in read mode using open method and pass filename and rb+ mode to it.
• Read binary file using load() function and store it in a variable say ‘filedata’.
• Set value of found variable to zero
• Create empty list object say ‘lst’
• Use for loop to iterate through student data one by one
• Check roll number present in student record using if loop within for loop
• If condition is TRUE then append list object with student data
• If condition is FALSE then set value of found variable to 1
• Write data into list object from binary file using dump method when value of found variable is 1.
• Print error message “Roll number does not found” using print function when found variable is zero.
• Close the binary file using close() function.
• The exit of the program.

Below is implementation code/Source code

import pickle
roll = input("Enter roll number whose record you want to delete:")
file = open("student.dat","rb+")
filedata = pickle.load(file)
found = 0
lst = [ ]
for x in filedata:
    if roll not in x['roll']:
        lst.append(x)
    else:
        found = 1
if found == 1:
    file.seek(0)
    pickle.dump(lst,file)
    print("Record Deleted")
else :
    print("Roll number does not found")
    
file.close()
file = open("student.dat","rb")
f = pickle.load(file)
print(f)
    

Below is Output

Enter roll number whose record you want to delete:11
Record Deleted
[{'roll': '13', 'sname': 'Sujata'}, {'roll': '15', 'sname': 'Lumbini'}]

Below is Snapshot of Executable code with Output

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