Question

Following is the structure of each record in a data file named "PRODUCT.DAT". {"prod_code":value, "prod_desc":value, "stock":value} The values for prod_code and prod_desc are strings, and the value for stock is an integer. Write a function in PYTHON to update the file with a new value of stock. The stock and the product_code, whose stock is to be updated, are to be input during the execution of the function.

Answer 1

Answer:

fp = open("file.txt", 'r')

fp.read()

(b) fp=open("file.txt", 'r')

4. What is the output of the following code fragment? Explain.

fout = file("output.txt", 'w')

fout.write("Hello, world!\n")

fout.write("How are you?")

fout.close()

file("output.txt").read()

5. Write the output of the following code with justification if the contents of the file ABC.txt are:

Welcome to Python Programming!

f1 = file("ABC.txt", "r")

size = len(f1.read())

print(size)

data = f1.read(5)

print(data)

6. Anant has been asked to display all the students who have scored less than 40 for Remedial Classes. Write

a user-defined function to display all those students who have scored less than 40 from the binary file

"Student.dat".

7. Give the output of the following snippet:

import pickle

list1, list2 = [2, 3, 4, 5, 6, 7, 8, 9, 10], []

for i in list1:

if (i%2==0 and i%4==0):

list2.append(i)

f = open("bin.dat","wb")

pickle.dump(list2, f)

f.close()

f = open("bin.dat", "rb")

data = pickle.load(f)

f.close()

for i in data:

print(i)

8. Following is the structure of each record in a data file named "PRODUCT.DAT".

{"prod_code": value, "prod_desc": value, "stock": value}

The values for prod_code and prod_desc are strings, and the value for stock is an integer.

Computer Science with Python–XII 4.24 9. Given a binary file “STUDENT.DAT”, containing records of the following type:

Write a function in Python to update the file with a new value of stock. The stock and the product_code,

whose stock is to be updated, are to be inputted during the execution of the function.