Quiz: Chapter 7 :Python Data Structures (Python for Everybody Specialization) Answers 2025

1. Given the architecture… where are files stored?
   ❌ Central Processor
   ❌ Main Memory
   ❌ Motherboard
   ✅ Secondary memory

Explanation: Files live on secondary storage (disk/SSD)—persistent storage outside RAM.

2. What is stored in a “file handle” returned from open()?
   ❌ The handle has a list of all files in a folder
   ❌ All the file data is read into the handle
   ✅ The handle is a connection to the file’s data
   ❌ The handle contains the first 10 lines of a file

Explanation: A file handle (file object) is a reference/connection you use to read from or write to the file; it does not contain the whole file automatically.

3. What do we use the second parameter of open() to indicate?
   ❌ How large we expect the file to be
   ❌ List of folders to search
   ✅ Whether we want to read data from the file or write data to the file
   ❌ What disk drive the file is stored on

Explanation: The mode string ('r', 'w', 'a', 'rb', etc.) tells Python whether to read, write, append, binary, etc.

4. Which Python function prompts the user for a file name to open?
   ❌ file_input()
   ❌ cin
   ❌ read()
   ✅ input()

Explanation: input() reads a line from the user (a filename string you can pass to open()).

5. Purpose of the newline character in text files?
   ✅ It indicates the end of one line of text and the beginning of another line of text
   ❌ It allows synchronized reading of multiple files
   ❌ It adds a new network connection
   ❌ It enables random movement throughout the file

Explanation: \n marks line boundaries in plain text files.

6. If xfile = open('mbox.txt'), what statement reads the file one line at a time?
   ❌ while (<xfile>) {
   ❌ while ((line = xfile.readLine()) != null) {
   ❌ while line = xfile.gets
   ✅ for line in xfile:

Explanation: In Python the idiomatic way is for line in fhandle: to iterate line-by-line lazily.

7. Purpose of this code that counts x = x + 1 in a loop over fhand:
   ❌ Convert lines to lower case
   ❌ Remove leading/trailing spaces
   ✅ Count the lines in the file ‘mbox.txt’
   ❌ Reverse the order of the lines

Explanation: The code increments a counter for each line read—so it counts lines.

8. If you see extra blank lines when printing file lines, which function likely solves it?
   ❌ split()
   ❌ trim()
   ✅ rstrip()
   ❌ ljust()

Explanation: Printed lines already include the trailing \n; print() adds another newline. Use line.rstrip() to remove the trailing newline (and other trailing whitespace) before printing.

9. How to avoid traceback when open(fname) fails on bad filename?
   ❌ signal handlers
   ❌ setjmp / longjmp
   ❌ try / catch / finally
   ✅ try / except

Explanation: Wrap open() in try: and handle except FileNotFoundError: (or generic except:) to print a friendly error instead of trace.

10. What does fhand.read() do?
    ✅ Reads the entire file into the variable inp as a string
    ❌ Turns text into a graphic image
    ❌ Prompts the user for a file name
    ❌ Checks if file exists and can be written

Explanation: .read() returns the whole file contents as one string (beware memory for large files).

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