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CBSE AISSCE 2016-2017 Marking Scheme for Computer Science
(Sub Code: 083 Paper Code 91/1 Delhi)

6 6, 24, 2, 6
+ 6, 24, 8
/ 6, 3
3
Answer: 3

(½ Mark for evaluation till each operator)
OR
(1 Mark for only writing the Final answer without showing stack
status)
4 (a) Differentiate between file modes ​r+​ and ​w+​ with respect to Python. 1
Ans ● r+ Opens a file for both reading and writing. The file pointer
placed at the beginning of the file.
● w+ Opens a file for both writing and reading. Overwrites the
existing file if the file exists. If the file does not exist, creates a
new file for reading and writing.

(1 mark for one of the correct difference )
OR
(½ Mark for each correct use of r+ and w+)
(b) Write a method in Python to read lines from a text file DIARY.TXT, and display 2
those lines, which are starting with an alphabet ‘P’.
Ans def display():
file=open('DIARY.TXT','r')
line=file.readline()
while line:
if line[0]=='P' :
print line
line=file.readline()
file.close() #IGNORE

(½ Mark for opening the file)
(½ Mark for reading all lines)
(½ Mark for checking condition for line starting with P)
(½ Mark for displaying line)
(c) Considering the following definition of class COMPANY, write a method in Python 3
to search and display the content in a pickled file COMPANY.DAT, where CompID is
matching with the value ‘1005’.

class Company:

def __init__(self,CID,NAM):
self.CompID = CID #CompID Company ID
self.CName = NAM #CName Company Name
self.Turnover = 1000
def Display(self):
print self.CompID,":",self.CName,":",self.Turnover
Ans import pickle
def ques4c( ):
f=Factory( )
file=open('COMPANY.DAT','rb')
try:

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