matplotlib: Plot the top N values, then squeeze in the rest

plot_top.py

import numpy as np
import matplotlib.pyplot as plt

  
def plot_top(names, values, n_top=10, 
             order=None,
             alpha=.25,
             ax=None, figsize=None):
    '''Plot the top N values, then squeeze in the rest
    
    Args:
        names: Array of labels
        values: Array of corresponding values
        n_top: How many values to plot. Default 10
        order: Order of values. If None, go from high to low.
        alpha: Transparency for the remaining values
        ax: Axis to plot to. If None, create new axis.
        figsize: Size of new axis (width, height)
    Returns:
        ax: Plot axis
    '''
    if order is None:
        order = np.argsort(values)[::-1]     # Order from high to low
    names = np.array(names)[order]
    values = np.array(values)[order]
    drop = np.isnan(values)
    names, values = names[~drop], values[~drop]
    n_total = len(names)
    n_left = n_total - n_top
    # Plot top values
    if ax is None:
        fig, ax = plt.subplots(1, 1, figsize=figsize)
    plt.sca(ax)
    plt.scatter(values[:n_top], range(n_top), color='b')
    # Plot the rest in one go
    x = np.linspace(n_top - .5, n_top + .5, n_left)
    plt.scatter(values[n_top:], x, color='b', alpha=alpha)
    # Labels
    yticks = np.concatenate([names[:n_top], ['The rest (N = %i)' % n_left]])
    plt.yticks(range(n_top+1), yticks)
    plt.gca().invert_yaxis()
    return ax

# Example
import pandas as pd
import seaborn as sns
sns.set_style('whitegrid')
populations = pd.read_json('https://raw.githubusercontent.com/samayo/country-json/master/src/country-by-population.json')
plot_top(populations['country'].values,
         populations['population'].values / 1000000, 
         n_top=10, figsize=(4, 8))
plt.xlabel('Population (millions)')
plt.show()