chapter 7 week 3 quiz

chapter 7 week 3 quiz

Quiz

 

1. Given the architecture and terminology we introduced in Chapter 1, where are files stored?
   
   1.   Main Memory
   2.   Central Processor
   3.   Motherboard
   4.   Secondary memory
2. What is stored in a "file handle" that is returned from a successful open() call?
   
   1.   The handle contains the first 10 lines of a file
   2.   The handle has a list of all of the files in a particular folder on the hard drive
   3.   All the data from the file is read into memory and stored in the handle
   4.   The handle is a connection to the file's data
3. What do we use the second parameter of the open() call to indicate?
   
   1.   Whether we want to read data from the file or write data to the file
   2.   How large we expect the file to be
   3.   The list of folders to be searched to find the file we want to open
   4.   What disk drive the file is stored on
4. What Python function would you use if you wanted to prompt the user for a file name to open?
   
   1.   read()
   2.   file_input()
   3.   cin
   4.   input()
5. What is the purpose of the newline character in text files?
   
   1.   It allows us to open more than one files and read them in a synchronized manner
   2.   It enables random movement throughout the file
   3.   It indicates the end of one line of text and the beginning of another line of text
   4.   It adds a new network connection to retrieve files from the network
6. If we open a file as follows:
   xfile = open('mbox.txt')
   
   What statement would we use to read the file one line at a time?
   
   
   1.   while() {
   2.   for line in xfile:
   3.   while((line = xfile.readLinr()) != null ) {
   4.   READ xfile INTO LINE
7. What is the purpose of the following Python code?
   fhand = open('mbox.txt')
   x = 0
   for line in fhand:
   x = x + 1
   print(x)
   1.   Convert the lines in mbox.txt to lower case
   2.   Count the lines in the file 'mbox.txt'
   3.   Reverse the order of the lines in mbox.txt
   4.   Remove the leading and trailing spaces from each line in mbox.txt
8. If you write a Python program to read a text file and you see extra blank lines in the output that are not present in the file input as shown below, what Python string function will likely solve the problem?
   From: stephen.marquard@uct.ac.za
   From: louis@media.berkeley.edu
   From: zqian@umich.edu
   From: rjlowe@iupui.edu
   ...
   1.   ljust()
   2.   rstrip()
   3.   trim()
   4.   startswith()
9. The following code sequence fails with a traceback when the user enters a file that does not exist. How would you avoid the traceback and make it so you could print out your own error message when a bad file name was entered?
   
   fname = input('Enter the file name: ')
   fhand = open(fname)
   1.   signal handlers
   2.   setjmp / longjmp
   3.   try / except
   4.   try / catch / finally
10. What does the following Python code do?
    fhand = open('mbox-short.txt')
    inp = fhand.read()
    1.   Prompts the user for a file name
    2.   Checks to see if the file exists and can be written
    3.   Reads the entire file into the variable inp as a string
    4.   Turns the text in the file into a graphic image like a PNG or JPG