app.py

###############################################
# Created by iiSeymour
# Changed by Mandeep Singh
# Changed date: 03/21/2019
# Licensce: free to use
#############################################

import local_data as sample_data
from flask import Flask, render_template
from altair import Chart, X, Y, Axis, Data, DataFormat
import pandas as pd

# load a simple dataset as a pandas DataFrame
from vega_datasets import data
cars = data.cars()
electricity = data.iowa_electricity()
barley_yield = data.barley()

app = Flask(__name__)


##########################
# Flask routes
##########################
# render index.html home page
@app.route("/")
def index():
    return render_template('index.html')


# render cars.html page
@app.route("/cars")
def show_cars():
    return render_template("cars.html")


# render iowa electricity.html
@app.route("/electricity")
def show_electricity():
    return render_template("electricity.html")


#########################
### Altair Data Routes
#########################

WIDTH = 600
HEIGHT = 300


@app.route("/data/waterfall")
def data_waterfall():
    chart = Chart(sample_data.df_water).mark_bar(color='gray').encode(
        X('Name', axis=Axis(title='Sample')),
        Y('Value', axis=Axis(title='Value'))).interactive()
    return chart.to_json()


@app.route("/data/line")
def data_line():
    chart = Chart(
        data=sample_data.df_list, height=HEIGHT,
        width=WIDTH).mark_line(color='green').encode(
            X('name', axis=Axis(title='Sample')),
            Y('data', axis=Axis(title='Value'))).interactive()
    return chart.to_json()


@app.route("/data/multiline")
def data_multiline():
    chart = Chart(
        data=sample_data.df_stocks, height=HEIGHT,
        width=WIDTH).mark_line().encode(
            color='symbol:N',
            x='date:T',
            y='price:Q',
        ).interactive()
    return chart.to_json()


@app.route("/data/stocks")
def stocks():
    chart = Chart(
        data=sample_data.df_stocks, height=HEIGHT,
        width=WIDTH).mark_bar().encode(
            color='symbol:N',
            x='date:T',
            y='price:Q',
        ).interactive()
    return chart.to_json()


@app.route("/data/scatter")
def scatter():
    chart = Chart(
        sample_data.df_0, height=HEIGHT, width=WIDTH).mark_circle().encode(
            x='name:N', y='y2:Q').interactive()
    return chart.to_json()


@app.route("/data/bar")
def data_bar():
    chart = Chart(
        data=sample_data.df_list, height=HEIGHT,
        width=WIDTH).mark_bar(color='yellow').encode(
            X('name', axis=Axis(title='Sample')),
            Y('data', axis=Axis(title='Value'))).interactive()
    return chart.to_json()


# Creates graph for cars
@app.route("/data/cars")
def cars_demo():

    chart = Chart(
        data=cars, height=700, width=700).mark_point().encode(
            x='Horsepower',
            y='Miles_per_Gallon',
            color='Origin',
        ).interactive()
    return chart.to_json()


# Creates graph for IOWA electricity consumption
@app.route("/data/electricity")
def electricity_demo():

    chart = Chart(
        data=electricity, height=700, width=700).mark_area().encode(
            x="year:T", y="net_generation:Q", color="source:N").interactive()
    return chart.to_json()


# Creates graph for IOWA electricity consumption
@app.route("/data/barley_yield")
def barley_yield_demo():

    chart = Chart(
        data=barley_yield, height=400, width=200).mark_bar().encode(
            x='year:O', y='sum(yield):Q', color='year:N',
            column='site:N').interactive()
    return chart.to_json()


if __name__ == "__main__":
    app.run(debug=True)