Non-English Column Names

[Gen]

Can Bokeh’s Hovertool print data if the Column name is non-English in a ColumnDataSource?

Here’s a quick example:

import pandas as pd
from bokeh.models.sources import ColumnDataSource
from bokeh.plotting import figure, show
from bokeh.models.tools import HoverTool

# Set up the data
non_english_col_name = '名前'
df = pd.DataFrame({
    non_english_col_name: ['a','b'],
    'x': [1,2],
    'y': [0,3]
})
source = ColumnDataSource(df)

# Create the glyphs
p = figure()
scatter = p.scatter(source = source)

# Create the Hovertool


hover_tool = HoverTool(renderers=[scatter],
                       tooltips=[('Name', f'@{non_english_col_name}'),
                                 ('x','@x'),
                                 ('y','@y')]
)
p.add_tools(hover_tool)
show(p)

Both x and y show up fine in the Hover, but the non-English column name (non_english_col_name) doesn’t display the data and treats it as a string literal. Is there a workaround for this other than re-naming the column name to an English name?

[Bryan]

@Gen column names that have spaces or sometimes other special characters in then Bokeh requires them to be enclosed in curly braces in the tooltip string. ^[1] Considering you are using an f-string as well, you will also have to use Python escape syntax for the literal braces, and it ends up looking like this, with three braces on each side:

tooltips=[('Name', f'@{{{non_english_col_name}}}')

This is mentioned in the middle of the Basic Tooltips section of the docs.

---

1. It’s also possible to just always use curly braces around column names e.g. to be consistent and not have to worry about which cases require them. ↩︎

[Gen]

Thank you, this is extremely helpful. I will just always make it a rule to use curly braces!