PRIP 4.3 Sumita Arora Solutions | Class 12 Computer Science

(a) What is the possible reason of above error ?
Answer: 

• import statement shows error because of absence of __init__.py file
• __init__.py is for packages. A package contains a collection of related modules.
• Files named __init__.py are used to mark directories on disk as Python package directories.
• The __init__.py file is usually empty

Note:
Since Python 3.3
Allowing implicit namespace packages means that the requirement to provide an __init__.py file can be dropped completely
The old way with __init__.py files still works as in Python 2.
i.e. above question has executed on python2, if you try it on python3.3+ it will work fine without __init__.py
for version above python3.3 no need of __init__.py in chk but required in test to import modules from test

for more visit here

(b) Rectify above problem.
Answer:  Add empty __init__.py file in chk folder and in test folder

(c) After rectifying, write command to import work module of above shown chk package
Answer: 

from chk import work
OR
import chk.work
OR
import chk.work as w

(d) After rectifying, write command to import newwork module of above shown chk package
Answer:

from chk.test import newwork 
OR
import chk.test.newwork
OR
import chk.test.newwork as nw

a) Complete code of delivery.py (make assumption)
Answer:

#deliver.py
"""
deliver

functions related to delivery of mails

"""
def send_mail():
    """
    send_mail

    shows all sent mails 
   
    """
    print("called send_mail")

def get_mail():
    """
    get_mail

    shows all received mails 
   
    """
    print("called get_mail")

def draft():
    """
    draft

    shows all drafted mails 

    """
    print("called outbox")

def outbox():
    """
    outbox

    shows all outbox mails 

    """
    print("called outbox")

def inbox():
    """
    inbox

    shows all inbox mails 

    """
    print("called inbox")

(b) Complete code of oldmail.py (make assumptions)
Answer:

#Oldmail.py

"""
Oldmail

contains functions to access old mails

"""

def fiveyr():
    """
    fiveyr

    used to show mails from last five years 
   
    """
    print("used to show mails from last five years")

def starred():
    """
    starred

    use to show all starred mails 

    """
    print("use to show all starred mails")

(c) Write command to display details of module delivery
Answer:

>>> import mailsys.deliver
>>> help(mailsys.deliver)
>>> from mailsys import deliver
>>> help(deliver)

(d) Write command to import get_mail() function
Answer:

>>> from mailsys.deliver import get_mail
>>> help(get_mail)

(e) Write command to import these modules : deliver and oldmail
Answer:

>>> from mailsys import deliver
>>> from mailsys.archive import Oldmail
>>> help(Oldmail)
>>> help(deliver)

(f) Write command to run draft() function
Answer:

>>> from mailsys import deliver
>>> deliver.draft()
Output:
called draft

(g) Write command to run fiveyr() function
Answer:

>>> from mailsys.archive import Oldmail
>>> Oldmail.fiveyr()
Output:
used to show mails from last five years