altair | Declarative statistical visualization library for Python | Data Visualization library

I generate a line chart in Altair. I'd like to control which lines are "on top" of the stack of lines. In my example here, I wish for the red line to be on top (newest date) and then descend down to the yellow (oldest date) to be on the bottom.

I tried to control this with the sort parameter of of alt.Color but regardless of sort='ascending' or sort='descending' the order of the line overlap will not change.

How can I control this? Was hoping I can do this without sorting my source dataframe itself.

Is there a way to change the color of just a single group in Altair plot, while leaving the rest the same? I like the default color scheme fine, but there is one group I want to change the color for.

For example, in a scatter-plot like this:

I have the following chart (code is at the end)

and I need to increase its width.

If I set alt.Chart(df, width=100, height=90) then the bar width of the group with fewer bars is too large, like this

If I set alt.Chart(df, height=90).mark_bar(size=20) then bars overlap, like this

I'm trying to set the x-axis domain to between 0-36, as some data I'm processing was collected in 6-week increments. Following the documentation i used the scale=alt.Scale(domain=[0,36]). However, this continues to show the chart up to 40.

Here is the code taken from the Altair documentation on color schemes.

I am working with a simple ML model with streamlit. It runs fine on my local machine inside conda environment, but it shows Error installing requirements when I try to deploy it on share.streamlit.io.
The error message is the following:

Does Vega/Vega-Lite/Altair have a builtin method to draw a special mark for empty bars? When x == x2 no mark is currently shown. Perhaps a vertical rule mark of the same expected bar color as derived from a third encoding? Or perhaps a semi-transparent bar mark covering an expanded region with a red border?

I would like myval to show the name of each car for each aggregated year, ex. "chevrolet chevelle malibu".

The [object Object] thing appears to be JavaScript related.

I have a visualization where I am trying to increase mark size and also have them touching (decrease the space in-between the marks) using altair. Is there a way to do this without simply using 'size='? I would like to make this adaptable to a function and not hardcode the size, but have it dependable on the data given.

Here is my current code so far: