When using a long legend name for a curve, the label on the data tooltip is cropped:
Several people online recommend using the text property of the data object to give names that are not cropped, and this has worked for me:
However, the legend name (set in the name property) still appears, and is cropped. Is there any possible way to have a legend, but set it so the names of the legends are not displayed on the tooltip?
Hi @mathieuboudreau,
You can specify what info shows up in the hover tooltip using the scatter.hoverinfo property. Here’s the docstring
Determines which trace information appear on hover. If `none`
or `skip` are set, no information is displayed upon hovering.
But, if `none` is set, click and hover events are still fired.
The 'hoverinfo' property is a flaglist and may be specified
as a string containing:
- Any combination of ['x', 'y', 'z', 'text', 'name'] joined with '+' characters
(e.g. 'x+y')
OR exactly one of ['all', 'none', 'skip'] (e.g. 'skip')
- A list or array of the above
The default is all, which shows everything. You’ll want to set it to something that doesn’t include name. Maybe 'x+y+text.
Hope that helps!
-Jon
Worked perfectly - thanks a lot @jmmease!
I still have a problem,
however this works well without hovertemplate,
If I have my customised template, then the hoverinfo is not working
this.Level ={
x: this.x,
y: this.y1,
xaxis:‘x’,
yaxis:‘y’,
hoverinfo: ‘x+y’,
hovertemplate:‘one:%{y}%
’+
‘two:%{y}%
’+
‘threel:%{y}mm
’ ,
type: ‘scatter’,
mode: ‘lines+markers’,
name: ‘Actual Level’,
line:{
color:’#aa1d5f’,
shape:‘spline’,
smoothing:’.4’
},
marker: {
color:’#ffffff’,
size: 10,
line: {color: ‘#aa1d5f’,width: 1}
}
};
In this case I still get a trailing legend name associated
If using hovertemplate you can set hoverlabel.namelength to 0 to hide the secondary bit 
Alternatively, you can put whatever you like in that secondary area (including nothing) when using hovertemplate by wrapping it in <extra></extra> inside the hovertemplate text.
Can you give a more detailed explanation? if possible an example? Thank you!
This section of the docs should help: Hover Text and Formatting | Python | Plotly
