Objective Questions

-------------------

1. What function is used to open a file?

   Answer: ``open``

#. The ``open`` function returns a 

   a. string

   #. list

   #. file object

   #. function

   Answer: file object

#. ``open`` function opens a file by default in write mode. T or F?

   Answer: False

#. The ``read`` method reads a file and returns the contents

   a. string

   #. list

   #. file object

   #. None of the above

   Answer: string

#. Given a file with ``hello.txt``, which looks like 

   ::

     Hello, World!

   What is the value of content, at the end of this code block::

     f = open('hello.txt')

     content = f.read()

     content = f.read()

     f.close()

   Answer: It is a null string. 

#. The following code block prints each line of ``hello.txt``::

     f = open('hello.txt')

     for line in f.read():

         print line

   True or False?

   Answer: False

#. Given a file with ``hello.txt``, which looks like 

   ::

     Hello, World!

   What is the output of ::

     f = open('hello.txt')

     for line in f:

         print line

     for line in f:

         print line

     f.close()

   Answer: Hello, World! is printed once.

           .. The actual answer should talk about blank lines, but I'm

           .. not sure if we should get into such detail. 

           .. Should this be made a multiple-choice?

#. Given a file with ``hello.txt``, which looks like 

   ::

     Hello, World!

   What is the output of ::

     f = open('hello.txt')

     for line in f:

         print line

     f.close()

     for line in f:

         print line

     f.close()

   Answer: Hello, World! is printed twice.

#. Given a file with ``hello.txt``, which looks like 

   ::

     Hello, World!

   What is the output of ::

     f = open('hello')

     for line in f:

         print line

     f.close()

     for line in f:

         print line

     f.close()

   Answer: IOError - No such file or directory: 'hello'

Larger Questions

----------------

1. f.read(size)

#. Print every alternate line of a file, starting at the first line. 

#. Print the file in reverse. Starting from the last line to the

   first.