Use Pandas index in Plotly Express

Question

Plotly Express allows me to easily plot a pandas dataframe, as explained in their examples. Rather than using a named column for x and a named column for y, I would like to

Answer 1

Reference: https://plot.ly/python/px-arguments/#using-the-index-of-a-dataframe

You can pass the index as reference explicitly.

So in your case, this would be:

import plotly.express as px
iris = px.data.iris()
fig = px.scatter(iris, x=iris.index, y="sepal_length")
fig.show()

--

BONUS QUESTION: what if iris has a pd.MultiIndex?

Use pd.MultiIndex.get_level_values.

import plotly.express as px

# dummy example for multiindex
iris = px.data.iris().set_index(['species', 'species_id', iris.index])

fig = px.scatter(
   iris, 
   x=iris.index.get_level_values(2), 
   y="sepal_length"
)

fig.show()

Answer 2

You can simply leave it blank, like so:

import plotly.express as px
iris = px.data.iris()
fig = px.scatter(iris, y="sepal_length")
fig.show()

Answer 3

You can only pass the column name at x & y parameters of px.scatter(). Seems there is no column named "index" in the iris dataset.