Python Bullet Charts

intapiuser · ‎03-02-2023

I've enjoyed creating bullet charts in Sisense for Cloud Data Teams using the technique outlined in this community post here. However, if we seek to further customize the look of a bullet chart, the R/Python integration comes in very handy! The above image is a bullet chart created using matplotlib, and allows quick interpretation of how well a business is tracking toward its goals.

Inputs:

df : a dataframe with 4 columns
- business - the name of the business/category
- base goal - a numerical value of the quota/base goal
- stretch goal - a numerical value of the target/stretch goal
- current value
color_code: an optional boolean parameter that color codes the current value based on whether the base and stretch goals have been met. Default value set to False

Snippet:

# SQL output is imported as a pandas dataframe variable called "df"
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

# Function: bullet_chart, creates a horizontal bar graph representing a bullet chart
# Inputs: (1) dataframe with 4 rows - the name of the column ("business"), "base goal" or the quota, "stretch goal" or the target, and the "current value" (2) Optional boolean paramater that shades the current value green/yellow/red based on whether the base/stretch goals have been met
# Output: matplotlib image representing a bullet chart
def bullet_chart(df,color_code=False):
  y_pos = np.arange(len(df.index))

  #assign coloring
  df["col"]="indigo"
  if (color_code==True):
    for i in y_pos:
      if(df["current value"][i]>=df["stretch goal"][i]):
        df["col"][i]="green"
      elif(df["current value"][i]>=df["base goal"][i]):
        df["col"][i]="gold"
      else:
        df["col"][i]="lightcoral"

  #Initialize plot
  fig, ax = plt.subplots()
  ax.barh(y_pos, df["stretch goal"], height=0.5, align='center', color='thistle', label="stretch goal")
  ax.barh(y_pos, df["base goal"], height=0.5, align='center', color='mediumorchid', label = "base goal")
  ax.barh(y_pos, df["current value"], height=0.2, align='center',color=df["col"])
  ax.set_yticklabels(df["business"])
  ax.set_yticks(y_pos)
  ax.invert_yaxis()

  #add data labels
  for i in y_pos:
    ax.text(df["current value"][i], i+0.05, df["current value"][i])

  #add legend and format borders
  plt.legend(loc=(0.35,1.0))
  ax.spines['left'].set_linewidth(0.2)
  ax.spines['bottom'].set_linewidth(0)
  ax.spines['right'].set_linewidth(0)
  ax.spines['top'].set_linewidth(0)
  fig.subplots_adjust(left=0.2, top=0.8)

  return fig

# Use Sisense for Cloud Data Teams to visualize a dataframe or an image by passing data to periscope.output()
periscope.image(bullet_chart(df, color_code=True))

Sisense Community

Python Bullet Charts