Sending Pandas DataFrame as JSON to CoreUI/React template

In this tutorial, we are going to use a CoreUI React template as and Python backend with Pandas to read a CSV and render in the UI as JSON Table.

Avkash Chauhan

Jun. 25, 20 · Tutorial

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Tutorial Objective

By the end of this tutorial, you will be able to do the following:

Core UI React Template
Python with Flask RESTful API
Using Pandas module to read a CSV from the web and collect rows as Pandas DataFrame
Convert Pandas DataFrame to JSON
Send JSON result in UI and render as HTML Table

Getting Starting Code

(Bootstrap Code to Start With):

https://github.com/Avkash/300seconds/tree/master/coreui_react_python_flask_starter

If you are interested in Full Stack Development — Getting Started (Part 1) tutorial to learn how we arrived here, please follow this Part1 tutorial.

Coding Exercise

Here are the steps you would need to take on both (frontend and backend) sides to make this full code working:

FrontEnd Coding:

Add a new page (CsvDataReader.js) to your core UI template
Add routes, navigation and menu support in the layout to launch your page when clicked
Add ts-react-json-table to your package.json and run “npm update”. This will let you use JsonTable react component to render a table from JSON data object.

Following the CsvDataReader.js code:

    JavaScript
   
 

     
    

      

     

      

     

     

    
x

          

         

          

         

            
          
import React, { Component, lazy, Suspense } from 'react';
import {
  Card,
  CardBody,
  CardFooter,
  CardHeader,
  CardTitle,
  Col,
  Row,
} from 'reactstrap';
import JsonTable from 'ts-react-json-table';
import GetRestObject from '../../api/ConnectServerGet';
import PostRestObject from '../../api/ConnectServerPost';
class CsvDataReader extends Component {
    constructor(props) {
      super(props);
  
      this.state = {
          csvDataObject:[]
      };
    }
  
    HelloGetRequestedDetails = () => {
      GetRestObject.GetRestRequest(`/v1/datareader`, getResultObj => {
          this.setState({
            csvDataObject:getResultObj   
          })
      });
    }
    renderColumnNames = (colmunList) => {
        return(
            colmunList.map( (item, index) => {
                return(
                    <span key={index} className="mr-1 text-default">{index+1}: {item}</span>
                )
            })
        )
    }
 
    renderCsvDataResults = () => {
        if (this.state.csvDataObject && this.state.csvDataObject.resultStatus && this.state.csvDataObject.resultData){
            var apiStatus = this.state.csvDataObject.resultStatus;
            var apiData = this.state.csvDataObject.resultData;
            if (apiStatus === 'SUCCESS' && apiData.length == 1){
                apiData = apiData[0]
                return(
                    <div>
                        <span className="text-success">Rows: <span className="text-primary"><b>{apiData.rows}</b></span></span>
                        <br/>
                        <span className="text-success">Columns: <span className="text-primary"><b>{apiData.cols}</b></span></span>
                        <br/>
                        <span className="text-success">Column Names: 
                            <span className="text-primary"><b>{this.renderColumnNames(apiData.columns)}</b></span>
                        </span>
                        <hr/>
                        <Card>
                            <CardHeader>All Rows</CardHeader>
                            <CardBody className="mb-1" style={{height:'400px', overflowY: "auto", overflow: "-moz-scrollbars-horizontal"}}>
                                <JsonTable rows={apiData.rowData} columns={apiData.columns} />
                            </CardBody>
                        </Card>
                    </div>
                )
            } else {
                return(
                    <div>
                        <span className="text-danger">{apiData[0].message}</span>
                    </div>
                )
            }
        }
    }
    componentDidMount(){
      this.HelloGetRequestedDetails()
    }
    loading = () => <div className="animated fadeIn pt-1 text-center">Loading...</div>
  
    render() {
  
      return (
        <div className="animated fadeIn">
          <Row>
            <Col md={12}>
              <h3>Data Reader Starter</h3>
              <hr/>
              {this.renderCsvDataResults()}
            </Col>
          </Row>
        </div>
    );
  }
}
export default CsvDataReader;

      

     

Backend Coding

Add support for API (/v1/datareader) by adding a resource

    Java
   
          x
         
# app.py
api.add_resource(DataHandlerFunction, '/v1/datareader')

2. Implement DataHandlerFunction in CsvDataHandler.py as below:

    Python
   
xxxxxxxxxx

from flask_restful import Api, Resource, reqparse
import pandas as pd
import requests
import io
class DataHandlerFunction(Resource):
    '''
    '''
    def get(self):
        result_status, result_data = CSVReaderToJson()
        return {'resultStatus': result_status, 'resultData': result_data}
def CSVReaderToJson():
    result_status = 'FAILURE'
    result_data = []
    csv_url = "https://raw.githubusercontent.com/cs109/2014_data/master/countries.csv"
    try:
        url_content = requests.get(csv_url).content
        csv_data = pd.read_csv(io.StringIO(url_content.decode('utf-8')))
        row_count = csv_data.shape[0]
        column_count = csv_data.shape[1]
        column_names = csv_data.columns.tolist()
        # Option [1]
        # row_json_data = csv_data.to_json(orient='records')
        # Option [2]
        final_row_data = []
        for index, rows in csv_data.iterrows():
            final_row_data.append(rows.to_dict())
        json_result = {'rows': row_count, 'cols': column_count, 'columns': column_names, 'rowData': final_row_data}
        result_data.append(json_result)
        result_status = 'SUCCESS'
    except:
        result_data.append({'message': 'Unable to process the request.'})
    return result_status, result_data

Final Source Code (Both CoreUI Frontend and Python Backend)

https://github.com/Avkash/300seconds/tree/master/coreui_react_python_flask_pandas_starter

YouTube Tutorial (00:43.30 Minutes)

That’s all, thank you.

JSON Pandas Template

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