EX06 - Strings

In Exercise 06 you will a function to abbreviate strings!

0. Pull the skeleton code

If you have already pulled the skeleton code for this week’s exercises, no worries about this step. You should already be good to go.

You will find the starter files needed by “pulling” from the course workspace repository. Before beginning, be sure to:

  1. Be sure you are in your course workspace. Open the file explorer and you should see your work for the course. If you do not, open your course workspace through File > Open Recent.
  2. Open the Source Control View by clicking the 3-node (circles) graph (connected by lines) icon in your sidebar or opening the command palatte and searching for Source Control.
  3. Click the Ellipses in the Source Control pane and select “Pull” from the drop-down menu. This will begin the pulling process from the course repository. It should silently succeed.
  4. Return to the File Explorer pane and open the exercises directory. You should see it now contains another directory named ex06. If you expand that directory, you should see the starter files for the Python programs in this exercise.

If the above did not work, try the following:

  1. Click the Ellipses in the Source Control pane and select “Pull, Push” from the drop-down menu. Then select “Pull from”. Then select “upstream” and the main option. This will begin the pulling process from the course repository. It should silently succeed.
  2. Return to the File Explorer pane and open the exercises directory. You should see it now contains another directory named ex06. If you expand that directory, you should see the starter files for the two Python programs in this exercise

1. Abbreviate

After pulling the skeleton code, above, you can find the starter code for in the file exercises/ex06/abbreviate.py.

We have provided the skeleton of a main function, discussed in lecture on Wednesday 5/26, and have denoted 2x TODO comments for you to complete in order.

First, find TODO 1 and notice it is at the “top-level” of the file (no indentation). Your job here is to define a function named abbreviate. It has the following signature expectations:

  1. It should have one str parameter.
  2. It should return a str value.

The str it returns should contain only the uppercase letter of the input string.

You may use the built-in isupper and islower functions to complete this exercise. These functions return the boolean value True if all characters in a given str are uppercase or lowercase, respectively. An example of their usage in the interactive REPL is below:

   $ python
   Python 3.9.1 (tags/v3.9.1:1e5d33e, Dec  7 2020, 17:08:21) [MSC v.1927 64 bit (AMD64)] on win32
   Type "help", "copyright", "credits" or "license" for more information.
   >>> example: str = "HAGS"
   >>> print(example.isupper())
   True

   >>> example_2: str = "have a GREAT summer"
   >>> print(example.islower())
   False

You can also use it to check if a specific character is uppercase or lowercase.

   $ python
   Python 3.9.1 (tags/v3.9.1:1e5d33e, Dec  7 2020, 17:08:21) [MSC v.1927 64 bit (AMD64)] on win32
   Type "help", "copyright", "credits" or "license" for more information.
   >>> example: str = "HAGS"
   >>> print(example[2].islower())
   False

   >>> example_2: str = "hElLoOOO"
   >>> print(example_2[1].isupper())
   True

Second, find TODO 2 inside of the main function’s body. Replace this comment with a statement that prompts the user for text that has uppercase letters in it. The main function should then make use of your abbreviate function to convert the string to an abbreviation and print it out.

You should now be able to run your program:

python -m exercises.ex06.abbreviate
Write some text with some uppercase letters: Happy BirthDay
The abbreviation is "HBD".
python -m exercises.ex06.abbreviate
Write some text with some uppercase letters: American Standard Code for Information Interchange
The abbreviation is "ASCII".

Requirements

  • For full credit, your printed abbreviation should be surrounded with quotations. (Hint: see this link)
  • Make sure to exactly match the output format shown in the example.

3. Make a Backup Checkpoint “Commit”

As you make progress on this exercise, making backups is encouraged. Note that you do not have to make a backup in order to submit your work, though you are encouraged to before each submission so that you can revert back to a previous point in your project if you accidentally change something you did not intend to.

  1. Open the Source Control panel (Command Palette: “Show SCM” or click the icon with three circles and lines on the activity panel).
  2. Notice the files listed under Changes. These are files you’ve made modifications to since your last backup.
  3. Move your mouse’s cursor over the word Changes and notice the + symbol that appears. Click that plus symbol to add all changes to the next backup. You will now see the files listed under “Staged Changes”.
    • If you do not want to backup all changed files, you can select them individually. For this course you’re encouraged to back everything up.
  4. In the Message box, give a brief description of what you’ve changed and are backing up. This will help you find a specific backup (called a “commit”) if needed. In this case a message such as, “Progress on Exercise 2” will suffice.
  5. Press the Check icon to make a Commit (a version) of your work.
  6. Finally, press the Ellipses icon (…), look for “Pull/Push” submenu, and select “Push to…”, and in the dropdown select your backup repository.

4. Submit to Gradescope for Grading

Login to Gradescope and select the assignment named “EX06 - Strings”. You’ll see an area to upload a zip file. To produce a zip file for autograding, return back to Visual Studio Code.

If you do not see a Terminal at the bottom of your screen, open the Command Palette and search for “View: Toggle Integrated Terminal”.

To produce a zip file for ex06, type the following command (all on a single line):

python -m tools.submission exercises/ex06

In the file explorer pane, look to find the zip file named “21.mm.dd-hh.mm-exercises-ex06.zip”. The “mm”, “dd”, and so on, are timestamps with the current month, day, hour, minute. If you right click on this file and select “Reveal in File Explorer” on Windows or “Reveal in Finder” on Mac, the zip file’s location on your computer will open. Upload this file to Gradescope to submit your work for this exercise.

Autograding will take a few moments to complete. If there are issues reported, you are encouraged to try and resolve them and resubmit. If for any reason you aren’t receiving full credit and aren’t sure what to try next, come give us a visit in office hours!