How to set a project variables with Python

me2

I am trying to set project variables that will be used by scenario recipes as dates. In a project the global variable is in the form of {"start_date": "10/27/2024"}. I am able to this in recipes and dashboards.

Using the python notebook, I am able to change the variables but now I want to make it dynamic based on current dates. Here is the code and I am having 2 issues.

First the format output from python not exactly the same format. I have not tried to use this in downstream recipes because I'm still trying to solve setting the variable.

new date 2024-10-28

Second when I try to replace the variable, I get a TypeError of errors in the python notebook.

TypeError: Object of type date is not JSON serializable

So I'm missing something in my code. Here is the code from Python notebook

import dataiku
from datetime import timedelta, date

project = dataiku.Project()
variables = project.get_variables()
x = date.today()
days_diff = timedelta(days=-7)
new_date = x + days_diff
variables["standard"]["start_date"] = new_date
project.set_variables(variables)

Thank you in advance for assisting!

Operating system used: Windows

Turribeach

As the update_variables() method documents the variables must be strings, numbers, booleans, lists or dicts. Dates are not supported. Convert to string and make the type is a string before you try to update the variable.

Marlan

Hi @me2,

Try converting the date to a string like this: new_date.strftime("%Y-%m-%d").

As a side note, I typically include single quotes in the variable definition, like this {"start_date": "'10/27/2024'"}. The advantage is that I can replace the date literal with expressions like CURRENT_DATE without changing the code that uses the variable (typically SQL in my case).

Marlan

me2

https://community.dataiku.com/discussion/comment/44826#Comment_44826

I tried converting and it printed "2024-10-28" but I get the same TypeError. I also tried modifying string to get "2024/10/28" with same error.

me2

https://community.dataiku.com/discussion/comment/44833#Comment_44833

Thank you @Marlan and @Turribeach I was able to get it to work in the Python notebook by changing the format then converting to a string.

# convert to string
new_date_str = str(new_date.strftime("%Y/%m/%d"))

# update variable
variables["standard"]["start_date"] = new_date_str

Now the final step, use it in a scenario step which I hope goes smoother than this did. 😉