getting_started_with_files/questions.rst
author Puneeth Chaganti <punchagan@fossee.in>
Wed, 01 Dec 2010 16:51:35 +0530
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Objective Questions
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-------------------
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.. A mininum of 8 questions here. 
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1. What function is used to open a file?
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   Answer: ``open``
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#. The ``open`` function returns a 
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   a. string
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   #. list
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   #. file object
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   #. function
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   Answer: file object
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#. ``open`` function opens a file by default in write mode. T or F?
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   Answer: False
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#. The ``read`` method reads a file and returns the contents
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   a. string
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   #. list
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   #. file object
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   #. None of the above
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   Answer: string
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#. Given a file with ``hello.txt``, which looks like 
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   ::
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     Hello, World!
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   What is the value of content, at the end of this code block::
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     f = open('hello.txt')
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     pre_content = f.read()
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     content = f.read()
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     f.close()
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   Answer: It is a null string. 
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#. The following code block prints each line of ``hello.txt``::
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     f = open('hello.txt')
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     for line in f.read():
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         print line
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   True or False?
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   Answer: False
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#. Given a file with ``hello.txt``, which looks like 
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   ::
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     Hello, World!
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   What is the output of ::
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     f = open('hello.txt')
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     for line in f:
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         print line
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     for line in f:
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         print line
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     f.close()
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   Answer: Hello, World! is printed once.
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           .. The actual answer should talk about blank lines, but I'm
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           .. not sure if we should get into such detail. 
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           .. Should this be made a multiple-choice?
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	   .. #[[Anoop: I think it will better if we make this multiple
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	      choice]]
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#. Given a file with ``hello.txt``, which looks like 
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   ::
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     Hello, World!
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   What is the output of ::
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     f = open('hello.txt')
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     for line in f:
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         print line
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     f.close()
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     for line in f:
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         print line
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     f.close()
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   Answer: Hello, World! is printed twice.
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#. Given a file with ``hello.txt``, which looks like 
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   ::
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     Hello, World!
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   What is the output of ::
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     f = open('hello')
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     for line in f:
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         print line
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     f.close()
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     for line in f:
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         print line
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     f.close()
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   Answer: IOError - No such file or directory: 'hello'
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Larger Questions
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----------------
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.. A minimum of 2 questions here. 
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1. What does ``f.read(size)`` do?
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#. Print every alternate line of a file, starting at the first line. 
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#. Print the file in reverse. Starting from the last line to the
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Puneeth Chaganti <punchagan@fossee.in>
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   136
   first.