unemployment heatmap

unemployment.py

from math import pi

import pandas as pd

from bokeh.io import show
from bokeh.models import BasicTicker, ColorBar, LinearColorMapper, PrintfTickFormatter
from bokeh.plotting import figure
from bokeh.sampledata.unemployment1948 import data

import numpy as np
from bokeh.models.tickers import FixedTicker

import colorcet as cc


data['Year'] = data['Year'].astype(str)
data = data.set_index('Year')
data.drop('Annual', axis=1, inplace=True)
data.columns.name = 'Month'

years = list(data.index)
months = list(data.columns)

# reshape to 1D array or rates with a month and year for each row.
df = pd.DataFrame(data.stack(), columns=['rate']).reset_index()

mapper = LinearColorMapper(palette=cc.palette['diverging_tritanopic_cwr_75_98_c20'], low=3, high=df.rate.max())
mapper_world = LinearColorMapper(palette=cc.palette['linear_blue_95_50_c20'], low=0, high=16)

TOOLS = "hover,save,pan,box_zoom,reset,wheel_zoom"

p = figure(title="US Unemployment ({0} - {1})".format(years[0], years[-1]),
           x_range=years, y_range=list(reversed(months)),
           x_axis_location="above", plot_width=900, plot_height=400,
           tools=TOOLS, toolbar_location='below',
           tooltips=[('date', '@Month @Year'), ('rate', '@rate')])

p.grid.grid_line_color = None
p.axis.axis_line_color = None
p.axis.major_tick_line_color = None
p.axis.major_label_text_font_size = "7px"
p.axis.major_label_standoff = 0
p.xaxis.major_label_orientation = pi / 3

p.rect(x="Year", y="Month", width=1, height=1,
       source=df,
       fill_color={'field': 'rate', 'transform': mapper},
       line_color=None)

n_ticks = 5
ticks = np.linspace(df.rate.min(), df.rate.max(), n_ticks).round(1)  
color_ticks = FixedTicker(ticks=ticks)

color_bar = ColorBar(color_mapper=mapper, major_label_text_font_size="7px",
                     ticker=color_ticks,
                     label_standoff=6, border_line_color=None, location=(0, 0))
                     
ticks_world = np.linspace(0, 16, n_ticks).round(1)  
color_ticks_world = FixedTicker(ticks=ticks_world)

color_bar_world = ColorBar(color_mapper=mapper_world, major_label_text_font_size="7px",
                     ticker=color_ticks_world,
                     label_standoff=6, border_line_color=None, location=(0, 0))
                     
p.add_layout(color_bar, 'right')
p.add_layout(color_bar_world, 'right')

show(p)