Use Dash to Build to Web Apps on Amazon DynamoDB Data

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems more effectively. With the CData Python Connector for Amazon DynamoDB, the pandas module, and the Dash framework, you can build Amazon DynamoDB-connected web applications for Amazon DynamoDB data. This article shows how to connect to Amazon DynamoDB with the CData Connector and use pandas and Dash to build a simple web app for visualizing Amazon DynamoDB data.

With built-in, optimized data processing, the CData Python Connector offers unmatched performance for interacting with live Amazon DynamoDB data in Python. When you issue complex SQL queries from Amazon DynamoDB, the driver pushes supported SQL operations, like filters and aggregations, directly to Amazon DynamoDB and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to Amazon DynamoDB Data

Connecting to Amazon DynamoDB data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

The connection to Amazon DynamoDB is made using your AccessKey, SecretKey, and optionally your Domain and Region. Your AccessKey and SecretKey can be obtained on the security credentials page for your Amazon Web Services account. Your Region will be displayed in the upper left-hand corner when you are logged into DynamoDB.

After installing the CData Amazon DynamoDB Connector, follow the procedure below to install the other required modules and start accessing Amazon DynamoDB through Python objects.

Install Required Modules

Use the pip utility to install the required modules and frameworks:

pip install pandas
pip install dash
pip install dash-daq

Visualize Amazon DynamoDB Data in Python

Once the required modules and frameworks are installed, we are ready to build our web app. Code snippets follow, but the full source code is available at the end of the article.

First, be sure to import the modules (including the CData Connector) with the following:

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.amazondynamodb as mod
import plotly.graph_objs as go

You can now connect with a connection string. Use the connect function for the CData Amazon DynamoDB Connector to create a connection for working with Amazon DynamoDB data.

cnxn = mod.connect("Access Key=xxx;Secret Key=xxx;Domain=amazonaws.com;Region=OREGON;")

Execute SQL to Amazon DynamoDB

Use the read_sql function from pandas to execute any SQL statement and store the result set in a DataFrame.

df = pd.read_sql("SELECT Industry, Revenue FROM Lead WHERE FirstName = 'Bob'", cnxn)

Configure the Web App

With the query results stored in a DataFrame, we can begin configuring the web app, assigning a name, stylesheet, and title.

app_name = 'dash-amazondynamodbedataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'

Configure the Layout

The next step is to create a bar graph based on our Amazon DynamoDB data and configure the app layout.

trace = go.Bar(x=df.Industry, y=df.Revenue, name='Industry')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='Amazon DynamoDB Lead Data', barmode='stack')
		})
], className="container")

Set the App to Run

With the connection, app, and layout configured, we are ready to run the app. The last lines of Python code follow.

if __name__ == '__main__':
    app.run_server(debug=True)

Now, use Python to run the web app and a browser to view the Amazon DynamoDB data.

python amazondynamodb-dash.py

Free Trial & More Information

Download a free, 30-day trial of the CData Python Connector for Amazon DynamoDB to start building Python apps with connectivity to Amazon DynamoDB data. Reach out to our Support Team if you have any questions.

Full Source Code

import os
import dash
import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import cdata.amazondynamodb as mod
import plotly.graph_objs as go

cnxn = mod.connect("Access Key=xxx;Secret Key=xxx;Domain=amazonaws.com;Region=OREGON;")

df = pd.read_sql("SELECT Industry, Revenue FROM Lead WHERE FirstName = 'Bob'", cnxn)
app_name = 'dash-amazondynamodbdataplot'

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
app.title = 'CData + Dash'
trace = go.Bar(x=df.Industry, y=df.Revenue, name='Industry')

app.layout = html.Div(children=[html.H1("CData Extension + Dash", style={'textAlign': 'center'}),
	dcc.Graph(
		id='example-graph',
		figure={
			'data': [trace],
			'layout':
			go.Layout(title='Amazon DynamoDB Lead Data', barmode='stack')
		})
], className="container")

if __name__ == '__main__':
    app.run_server(debug=True)