Multiple color argument in plotly in python

Question

>df.to_clipboard(sep=',', index=True)

,Country,Type,Year,Count
0,USA,A,1980,0.54
1,USA,A,1990,0.53
2,USA,A,2000,0.8
3,USA,A,2010,0.81
4,USA,A,2020,0.57
5,USA,B,1980,0.79
6,USA,B,1990,0.67
7,USA,B,2000,0.34
8,USA,B,2010,0.52
9,USA,B,2020,0.29
10,Canada,A,1980,0.91
11,Canada,A,1990,0.84
12,Canada,A,2000,0.85
13,Canada,A,2010,0.98
14,Canada,A,2020,0.81
15,Canada,B,1980,0.57
16,Canada,B,1990,0.61
17,Canada,B,2000,0.87
18,Canada,B,2010,0.16
19,Canada,B,2020,0.43

My objective is make a bar plot in plotly.

I did

import plotly.express as px
fig = px.bar(df, x="Year",y='Count',barmode='group',color="Country",hover_data=["Type"])
fig.show()

I get

I want Type A & Type B to have different colors, and preferable additional separate legend. I tried:

fig = px.bar(cnt, x="Year",y='Count',barmode='group',color=["Country","Type"],hover_data=["Type"])

but this gives error.

Answer 1

Using color to illustrate two different dimensions of your data would, in my opinion, quickly become very confusing. Unless you were able to use different shades of the same color. But even that would become messy with many categories. Luckily, plotly now provides another way to highlight multiple dimensions, namely Patterned Bar Charts with Plotly Express:

fig = px.bar(df, x="Year",y='Count',barmode='group',color="Country",hover_data=["Type"], pattern_shape = 'Type')

Plot 1

And you can change how the bars are grouped or stacked through barmode:

fig = px.bar(df, x="Year",y='Count',barmode='stack',color="Country",hover_data=["Type"], pattern_shape = 'Type')

Plot 2

Complete code

import pandas as pd
import plotly.express as px
import plotly.graph_objects as go

df = pd.DataFrame({'Country': {0: 'USA',
  1: 'USA',
  2: 'USA',
  3: 'USA',
  4: 'USA',
  5: 'USA',
  6: 'USA',
  7: 'USA',
  8: 'USA',
  9: 'USA',
  10: 'Canada',
  11: 'Canada',
  12: 'Canada',
  13: 'Canada',
  14: 'Canada',
  15: 'Canada',
  16: 'Canada',
  17: 'Canada',
  18: 'Canada',
  19: 'Canada'},
 'Type': {0: 'A',
  1: 'A',
  2: 'A',
  3: 'A',
  4: 'A',
  5: 'B',
  6: 'B',
  7: 'B',
  8: 'B',
  9: 'B',
  10: 'A',
  11: 'A',
  12: 'A',
  13: 'A',
  14: 'A',
  15: 'B',
  16: 'B',
  17: 'B',
  18: 'B',
  19: 'B'},
 'Year': {0: 1980,
  1: 1990,
  2: 2000,
  3: 2010,
  4: 2020,
  5: 1980,
  6: 1990,
  7: 2000,
  8: 2010,
  9: 2020,
  10: 1980,
  11: 1990,
  12: 2000,
  13: 2010,
  14: 2020,
  15: 1980,
  16: 1990,
  17: 2000,
  18: 2010,
  19: 2020},
 'Count': {0: 0.54,
  1: 0.53,
  2: 0.8,
  3: 0.81,
  4: 0.57,
  5: 0.79,
  6: 0.67,
  7: 0.34,
  8: 0.52,
  9: 0.29,
  10: 0.91,
  11: 0.84,
  12: 0.85,
  13: 0.98,
  14: 0.81,
  15: 0.57,
  16: 0.61,
  17: 0.87,
  18: 0.16,
  19: 0.43}})

fig = px.bar(df, x="Year",y='Count',barmode='group',color="Country",hover_data=["Type"], pattern_shape = 'Type')

fig.show()