Plotnine : How to remove legend boxes around lines in geom_line()

Question

Consider the following plotnine plot. How do I remove the pseudo boxes around the lines in the the legend (circled in the screenshot). These pseudo boxes don't appear in ggplot.

I have looked at all the options in theme, but none do the trick... https://plotnine.readthedocs.io/en/stable/generated/plotnine.themes.theme.html

import numpy as np
import pandas as pd
from plotnine import *


df = pd.DataFrame({
    'date':pd.date_range('1/1/2000', freq='A', periods=20),
    'a': np.random.uniform(0.01,0.03,20),
    'b': np.random.uniform(0.02,0.04,20),
})

df = pd.melt(df, id_vars=['date'])


p = (ggplot(df,aes(x='date',y='value',color='variable'))
  + theme_light()
  + geom_line(size=1.15)
  + labs(x=None, y=None)
  + scale_x_date(expand=(0,0), breaks=pd.date_range(start='2001-1-1', end='2019-1-1', periods=10), labels=lambda l: [v.strftime("%Y") for v in l])
  + scale_color_manual(('#50C878','#F75394'))
  + theme(
      legend_title=element_blank(),
      legend_direction='horizontal',
      legend_position='bottom',
      legend_box_spacing=0.25,
      legend_background=element_blank(),
      panel_grid_minor = element_blank(),
      panel_grid_major_x = element_blank(),
      panel_border = element_blank(),
  )
)
p

score 2 · Accepted Answer · answered Nov 16 '21 at 21:05

One option to achieve your desired result would be to set the color of the legend key to "white" or more generally the background color via `legend_key=element_rect(color = "white"):

import numpy as np
import pandas as pd
from plotnine import *


df = pd.DataFrame({
    'date':pd.date_range('1/1/2000', freq='A', periods=20),
    'a': np.random.uniform(0.01,0.03,20),
    'b': np.random.uniform(0.02,0.04,20),
})
df = pd.melt(df, id_vars=['date'])

p = (ggplot(df,aes(x='date',y='value',color='variable'))
  + theme_light()
  + geom_line(size=1.15)
  + labs(x=None, y=None)
  + scale_x_date(expand=(0,0), breaks=pd.date_range(start='2001-1-1', end='2019-1-1', periods=10), labels=lambda l: [v.strftime("%Y") for v in l])
  + scale_color_manual(('#50C878','#F75394'))
  + theme(
      legend_title=element_blank(),
      legend_key=element_rect(color = "white"),
      legend_direction='horizontal',
      legend_position='bottom',
      legend_box_spacing=0.25,
      legend_background=element_blank(),
      panel_grid_minor = element_blank(),
      panel_grid_major_x = element_blank(),
      panel_border = element_blank()
  )
)
p

Plotnine : How to remove legend boxes around lines in geom_line()

1 Answers1