Hi community,
I want the plot axes tick to be formatted as ‘100km’ or ‘1000m’. I know that plotly supports D3 number formatting, there are examples of adding prefix and symbols in the documentation but I couldn’t find a way to add a postfix to the numbers.
If anyone can help me out here, I’ll be very greatful.
Thanks 
Hi @dataturnsmeon you can add suffix to axes ticks as follow:
fig.update_layout(
# on the y-axis
yaxis_ticksuffix="m",
# on the colorbar
coloraxis_colorbar_ticksuffix="m",
# To specify which tick should have suffix
yaxis_showticksuffix="all" # or "first" or "last"
)
See the reference for more info.
You cannot have a suffix that changes for metres and kilometres but you could take advantage of the fact that D3 can do power of 1000 suffix (default behaviour for numeric ticks).
Sorry to bother you again, but do you know how to replace “,” (comma) separator to “.” (dot) for thousands?
Eg: 100,000 → 100.000
In D3 we can use locale formatter but I don’t think that’s supported with plotly.
Hi @dataturnsmeon,
I am not sure if there’s an easy way to do this with D3 formatting, but I know a workaround that you can use in your python code.
In the below example I am setting the start, end and step-size for the ticks on y axis and by using string formatting I am just replacing the comma with a period.
import plotly.express as px
data_canada = px.data.gapminder().query("country == 'Canada'")
fig = px.bar(data_canada, x='year', y='pop')
t_start = 0
t_end = 35000000
t_diff = 5000000
fig.update_yaxes(
range=[t_start, t_end],
dtick=t_diff,
tickvals=[x for x in range(0, t_end + t_diff, t_diff)],
ticktext=[
"{:,}".format(x).replace(",", ".") for x in range(0, t_end + t_diff, t_diff)
],
tickmode="array",
)
fig.show()
Hope this helps
