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import pandas as pd
import numpy as np
import os
from bqplot import (
    LogScale, LinearScale, OrdinalColorScale, ColorAxis,
    Axis, Scatter, Lines, CATEGORY10, Label, Figure, Tooltip
)
from ipywidgets import HBox, VBox, IntSlider, Play, jslink
    
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initial_year = 1800
    
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data = pd.read_json(os.path.abspath('./nations.json'))
    
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def clean_data(data):
    for column in ['income', 'lifeExpectancy', 'population']:
        data = data.drop(data[data[column].apply(len) <= 4].index)
    return data
def extrap_interp(data):
    data = np.array(data)
    x_range = np.arange(1800, 2009, 1.)
    y_range = np.interp(x_range, data[:, 0], data[:, 1])
    return y_range
def extrap_data(data):
    for column in ['income', 'lifeExpectancy', 'population']:
        data[column] = data[column].apply(extrap_interp)
    return data
    
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data = clean_data(data)
data = extrap_data(data)
    
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income_min, income_max = np.min(data['income'].apply(np.min)), np.max(data['income'].apply(np.max))
life_exp_min, life_exp_max = np.min(data['lifeExpectancy'].apply(np.min)), np.max(data['lifeExpectancy'].apply(np.max))
pop_min, pop_max = np.min(data['population'].apply(np.min)), np.max(data['population'].apply(np.max))
    
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def get_data(year):
    year_index = year - 1800
    income = data['income'].apply(lambda x: x[year_index])
    life_exp = data['lifeExpectancy'].apply(lambda x: x[year_index])
    pop =  data['population'].apply(lambda x: x[year_index])
    return income, life_exp, pop
    
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tt = Tooltip(fields=['name', 'x', 'y'], labels=['Country Name', 'Income per Capita', 'Life Expectancy'])
    
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year_label = Label(x=[0.75], y=[0.10], font_size=52, font_weight='bolder', colors=['orange'],
                   text=[str(initial_year)], enable_move=True)
    
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x_sc = LogScale(min=income_min, max=income_max)
y_sc = LinearScale(min=life_exp_min, max=life_exp_max)
c_sc = OrdinalColorScale(domain=data['region'].unique().tolist(), colors=CATEGORY10[:6])
size_sc = LinearScale(min=pop_min, max=pop_max)
    
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ax_y = Axis(label='Life Expectancy', scale=y_sc, orientation='vertical', side='left', grid_lines='solid')
ax_x = Axis(label='Income per Capita', scale=x_sc, grid_lines='solid')
    
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# Start with the first year's data
cap_income, life_exp, pop = get_data(initial_year)
    
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wealth_scat = Scatter(x=cap_income, y=life_exp, color=data['region'], size=pop,
                      names=data['name'], display_names=False,
                      scales={'x': x_sc, 'y': y_sc, 'color': c_sc, 'size': size_sc},
                      default_size=4112, tooltip=tt, animate=True, stroke='Black',
                      unhovered_style={'opacity': 0.5})
    
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nation_line = Lines(x=data['income'][0], y=data['lifeExpectancy'][0], colors=['Gray'],
                       scales={'x': x_sc, 'y': y_sc}, visible=False)
    
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time_interval = 10
    
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fig = Figure(marks=[wealth_scat, year_label, nation_line], axes=[ax_x, ax_y],
             title='Health and Wealth of Nations', animation_duration=time_interval)
    
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year_slider = IntSlider(min=1800, max=2008, step=1, description='Year', value=initial_year)
    
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def hover_changed(change):
    if change.new is not None:
        nation_line.x = data['income'][change.new + 1]
        nation_line.y = data['lifeExpectancy'][change.new + 1]
        nation_line.visible = True
    else:
        nation_line.visible = False
        
wealth_scat.observe(hover_changed, 'hovered_point')
    
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def year_changed(change):
    wealth_scat.x, wealth_scat.y, wealth_scat.size = get_data(year_slider.value)
    year_label.text = [str(year_slider.value)]
year_slider.observe(year_changed, 'value')
    
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play_button = Play(min=1800, max=2008, interval=time_interval)
jslink((play_button, 'value'), (year_slider, 'value'))
    
This is a recreation in D3 of Gapminder’s Wealth & Health of Nations, made famous by Hans Rosling’s memorable 2006 TED talk. It shows the dynamic fluctuation in per-capita income (x), life expectancy (y) and population (radius) of 180 nations over the last 209 years. Nations are colored by geographic region; mouseover to read their names.
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VBox([HBox([play_button, year_slider]), fig])