Module 7

Question 1

How do you open a file

Answer 1

open it: supply the name of the file stored on disk and the mode in which the file is to be opened

Question 2

infile = open (“input.txt”, “r”)

Answer 2

opens the file for reading (indicated by the string argument “r”) and returns a file object that is associated with the name input.txt

Question 3

all operations for accessing a file are made via what?

Answer 3

the file object

Question 4

what are text files commonly used for?

Answer 4

to store information. The most “portable” type of data files

Question 5

examples of text files that are created with a simple text editor

Answer 5

windows notepad, HTMML, and Python source code

Question 6

What are some important things to keep in mind when opening a file for reading?

Answer 6

• the file must exist (and otherwise
  be accessible) or an exception occurs
• The file object returned by the open function must be saved in a
  variable
• All operations for accessing a file are made via the file object

Question 7

file objects allows us to…

Answer 7

to use, access, and manipulate all the user accessible files.

Question 8

outfile = open(“output.txt”, “w”)

Answer 8

To open a file for writing, you provide the name of the file as the first argument to the open function and the string “w” as the second argument

f the output file already exists, it is emptied before the new data is
written into it
If the file does not exist, an empty file is created

Question 9

closing files

Answer 9

• When you are done processing a file, be sure to close the file using the close() method:

infile.close()
outfile.close()

• If your program exits without closing a file that was opened for
  writing, some of the output may not be written to the disk file