Contents

1. Setup

CS1302 Introduction to Computer Programming

1.1. JupyterHub

1.1.1. How to access the JupyterHub Server?

  1. Enter the url of the Jupyterhub server ltjh.cs.cityu.edu.hk in a web browser.

  2. Enter your EID and Password in the fields Username and Password respectively.

  3. Click the Sign In button.

https://www.cs.cityu.edu.hk/~ccha23/cs1302/Login.gif

Tips

  • If the browser is stuck at the following page loading the server, refresh your browser.
    server stuck

  • If you see the following page with My Server button, click on that button.
    server start

  • If you see the Start My Server button instead, click on that button to start your server.
    server stopped

  • For other issues, try logging out using the Logout button at the top right-hand corner, and then logging in again. You may also click the Control Panel button and restart your server.

1.1.2. How to access course materials?

  1. Click on the Assignments tab, and ensure cs1302 is chosen in the drop down list.

  2. In the Released assignments panel, click the button Fetch to download Lab1.

  3. Lab1 should appear in the Downloaded assignments panel.

  4. Click on the little arrow next to Lab1 to show its content.

  5. Ctrl-Click on Lab1 to open the assignment folder on a new browser tab.

  6. On the new browser, click the folder cs1302 to navigate to the notebook Setup.ipynb.

  7. Click on Setup.ipynb to open the notebook.

https://www.cs.cityu.edu.hk/~ccha23/cs1302/Fetch.gif

Tips

  1. Note that all the downloaded course materials will be placed under the cs1302 folder of your home directory by default, so you need not go to the Assignments tab again to open the downloaded materials. E.g., you can access the Setup.ipynb notebook as follows:

    1. Going to the File tab, which is the default JupyterHub homepage after login or when you click the logo on the top left-hand corner.

    2. Enter the notebook URL ltjh.cs.cityu.edu.hk/user-redirect/tree/cs1302/Lab1/Setup.ipynb. (See the documentation for details.)

  2. If for any reason you want to Fetch Lab1 again, you have to first rename your Lab1 folder to a different name such as Lab1_orig. You can do so by selecting the folder and click rename. You can also remove the folder by evaluating !rm -rf ~/cs1302/Lab1 in a code cell. (Be very cautious as removed folders cannot be recovered.)

1.2. Jupyter Notebook

1.2.1. How to complete a lab assignment?

After opening the Lab1 notebook Setup.ipynb:

  1. Click Help->User Interface Tour to learn the jupyter notebook interface.

  2. Click Help->Notebook Help and skim through the tutorials on Running Code and Working with Markdown Cells.

Exercise In learning a new computer language, the first program to write is often the “Hello, World!” program, which says Hello to the world. Type the program print('Hello, World!') below and run it with Shift+Enter.

### BEGIN SOLUTION
print('Hello, World!')
### END SOLUTION

Hello, World!

We often ask you to write a code in a particular cell. Make sure you fill in any place that says YOUR CODE HERE or “YOUR ANSWER HERE”.

In order to check your work thoroughly, there will visible and hidden test cases. The following is a visible test you can run to check your answer: The test returns an assertion error only if your program does not print the correct message.

# Run this test cell right after running your "Hello, World!" program.
import sys, io
old_stdout, sys.stdout = sys.stdout, io.StringIO()
exec(In[-2])
printed = sys.stdout.getvalue()
sys.stdout = old_stdout
assert printed == 'Hello, World!\n'

Tips

  1. You can repeatedly modify your solution and run the test cell until your solution passes the test. You are not required to know how the test cell is written.

  2. To assess your solution thoroughly, we often run new tests hidden from you after you have submitted your notebook. There is no partial credit for a partially correct solution that works for the visible test but fails for the hidden test. Therefore, you should ensure your solution works in general rather than just the visible tests.

  3. You can click the Validate button to run all the visible tests.

  4. If you open the same notebook multiple times in different browser windows, be careful in making changes in different windows. Inconsistent changes may lead to conflicts or loss of your data.

  5. If your notebook fails to run any code, the Kernel might have died. You can restart the kernel with Kernel->Restart. If restarting fails, check your code cells to see if there is any code that breaks the kernel.

1.2.2. How to submit a notebook

  • Although Lab1 does not count towards your final grade, you are required to submit it, to get familiar with the procedure.

  • Before you submit, make sure everything runs as expected:

    1. Restart the kernel: Kernel->Restart

    2. run all cells: Cell->Run All

To submit your notebook:

  1. Go to Assignment tab of JupyterHub where you fetched the Lab assignment.

  2. Expand the Lab1 folder and click the validate button next to the notebook(s) to check if all visible tests pass.

  3. Click Submit to submit your notebook.

  4. You may submit as many times as you wish before the due date as we collect your latest submission for grading.

    • No late submission will be collected without valid justifications.

    • Double check that you have submitted the correct Lab assignment.

    • You are responsible for recording your submission attempt with a valid timestamp in case of technical issues.

Tips

  1. You normally have at least 5 days to work on the lab after your lab session.

  2. You can check the due dates of all the labs from the course homepage.

  3. You may seek help from us or your classmates. However, you must write your own solution and indicate who your collaborators are using the code:

COLLABORATORS = ['WONG Xiu Fong', 'LEE Man Kit']

1.3. Advanced Usage

1.3.1. How to print or backup a notebook?

To convert a notebook to pdf, we can print it to pdf instead:

  • File->Print Preview

However, animation and video cannot be properly printed. You are highly recommended to takes notes on the dynamic notebook instead on the hard copy.

To download a copy of your notebook:

  • File->Download as->Notebook (.ipynb)

You can run the notebook

However, you would need to learn how to manage and install the additional packages required by the course.

1.3.2. Jupyter Lab and extensions

Instead of the classic notebook interface, you may also play with the new interface called JupyterLab by visiting ltjh.cs.cityu.edu.hk/user-redirect/lab/.

Note that the new interface does not support the validation and submission of lab assignment. It is currently under active development on GitHub, so be prepared to see bugs.

You may use the visual debugger in JupyterLab to debug a jupyter notebook. To do you, you should open the notebook and choose XPython as the kernel.

Both the notebook/lab interface is extensible. For the notebook interface, you can enable extensions from the nbextensions page.

1.3.3. Visual Studio Code

For a complete IDE experience, you can open VS Code as follows:

13. Review Questions 2. Card guessing game