Example of matplotlib barplot with accumulative ratio on 2nd axis.

mpl_bar_exaple_with_ratio.py

"""Example of matplotlib barplot with accumulative ratio on 2nd axis."""
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import seaborn as sns

# Plot with seaborn darkgrid style
% matplotlib inline
sns.set(style="darkgrid", palette="muted", color_codes=True)

# Generate toy data
df = pd.DataFrame({'group': ['A', 'B', 'C', 'D', 'E'],
                   'value': [20, 30, 10, 50, 40]})

# Genarate x coorinate point
# matplotlib Barplot require x-coordinate to point
x_idx = np.arange(df.shape[0])

# Get fig and ax to plot within
fig, ax = plt.subplots()

# Add barplot(1st axis)
bar = ax.bar(left=x_idx,
             height=df['value'],
             tick_label=df['group'],
             alpha=0.7
             )

# Add x/y label to 1st axis
ax.set_xlabel('Group')
ax.set_ylabel('Value[]')

# Add annotation to 1st axis
margin = 1
for x, y in zip(x_idx, df['value']):
    ax.text(x, y + margin, y, color='b')

# Calc accumulative ratio as secondaly axis value
df['accumulative_ratio'] = df['value'].cumsum() / df['value'].sum()

# Plot lines with secondaly axis
ax2 = ax.twinx()
line = ax2.plot(x_idx,
                df['accumulative_ratio'],
                ls='--',
                marker='o',
                color='r'
                )

# Add x/y label to 1st axis
ax2.set_ylabel('Accumulaive ratio[]')
ax2.grid(visible=False)

# Add annotation to 2nd axis
margin = 0.08
for x, y in zip(x_idx, df['accumulative_ratio']):
    ax2.text(x, y + margin, '{:.1f}'.format(y), color='r')

plt.legend(handles=(bar[0], line[0]),
           labels=('Value', 'Accumulaive_ratio'))

plt.suptitle('Example of barplot with secondaly axis.')
plt.show()