Common Troubleshooting Tips

NameError: name ‘ok’ is not defined
NameError: name ‘variable_name’ is not defined
NameError: name ‘make_array’ is not defined
TypeError: ‘float’ object is not callable
Tab completion doesn’t work
I downloaded the notebook file but it saves as the (.ipynb.json) extension, so whenever I upload it to Gradescope, it fails.
Frequently Asked Questions (FAQ)

NameError: name ‘ok’ is not defined

If you get an error

NameError: name 'ok' is not defined

Solution: run the code cell that says from client.api.notebook import Notebook in it (in Lab01 this cell is in section 1.5 Submitting your work). You will need to run this cell every time you start a new Jupyter session or restart the kernel.

NameError: name ‘variable_name’ is not defined

If you run your tests and recieve a lot of errors of the form:

NameError: name 'variable_name' is not defined

you may not have run the cells where these variables were defined. Or, you may have run the cells but then closed the session.

Solution: run the notebook from top to bottom.

Cell -> Run All

NameError: name ‘make_array’ is not defined

Make sure that you imported the datascience module. Run the cell that says

from datascience import *

TypeError: ‘float’ object is not callable

Alternatively, you might get TypeError: 'int' object is not callable.

This error happens when the variable that we are trying to assign is not correctly defined, which means that something is off on the right side of the assignment sign.

For example, in Python, we cannot write y = 2x, because 2 is a literal and x is a variable, so we need to make sure that there is an operator between them, which in this case should be a multiplication. Re-writing the expression as y = 2*x fixes the error.

Tab completion doesn’t work

If you start typing a variable name, press TAB on the keyboard, and nothing happens, there is probably no variable or function that starts with what you typed.

The TAB completion depends on running the previous cell where the variable or function is defined. Make sure you run that cell first, and then try again and hit TAB. Occasionally, you need to press TAB twice for it to work correctly.

Update Oct.8: We noticed that the tab completion only works within the cell in which the variable is defined. We are looking into it to see if the Jupyter notebooks got updated to remove this feature or if it is a setting that we need to change. Stay tuned!

I downloaded the notebook file but it saves as the (.ipynb.json) extension, so whenever I upload it to Gradescope, it fails.

You need to verify that the extension of the saved notebook file is .ipynb.

Occasionally, your operating system will rename it to be .ipynb.json, so you need to change it into .ipynb with nothing following it.

Update Oct.14: If the above doesn’t work (for example, if Gradescope adds the .ipynb.json extension even if you saved it with .ipynb), try using a different browser. For students with Mac laptops who were using Safari, the following fixed the issue:

Open the notebook in Google Chrome
Follow the steps about saving and downloading at the bottom of the lab
If asked which application it should use to open the file when you are downloading it select textEdit (if you don’t have textEdit try others until it works)

Frequently Asked Questions (FAQ)

I am unable to add this course on GOLD, the error is saying that the 4 digit code is invalid.

Verify that you are registering for the correct section of the class. You can try registering for another section and see if it works. Note: You can go ahead and attend the lab session that works best for you; no need to switch the registration.

If you are running into a different issue, send an email to the CS Undergraduate Advisor (ugradhelp @ cs.ucsb.edu) to see if we can get some explanation and/or assistance with this issue and CC Prof. K on your email. Make sure to include your PERM number in that email.

Where / when the lecture recordings will be posted?

Lecture recordings will be linked on the Schedule page for each corresponding lecture.

If we are in Weeks 1-2 and you don’t see the recordings, that means we haven’t been able to upload them just yet. Please, don’t email us or post on Piazza asking about the recordings, doing so will not make them appear any faster, since we are trying our best to get them uploaded as quickly as we are able (and as our Internet allows).

We apologize for any inconvenience the delay might have caused. We thank you for your patience and understanding.

I haven’t received an email about being added to Gradescope / Piazza. What should I do?

Please make sure that you are registered for this course on GOLD.

If you are having an issue with your registration, see the question above about adding this course on GOLD.

If you verified that you are enrolled in this course, send Prof. K an email including [DS 1] in the subject line and letting her know that you need to be added to Piazza and/or Gradescope.

I am unable to see the class when I log into Gradescope.

Make sure that you created your account using @umail.ucsb.edu (not @ucsb.edu).

SBCC students: check which address the Gradescope email was sent to; verify that you are using the email that was in the Gradescope’s “To:” field.

I am unable to see the class when I log into Piazza.