Pupli

from flask import request

Query Arguments

@app.route('/query-example')
def query_example():
    language = request.args.get('language') #if key doesn't exist, returns None

    return '''<h1>The language value is: {}</h1>'''.format(language)

Form Data

@app.route('/form-example', methods=['GET', 'POST']) #allow both GET and POST requests
def form_example():
    if request.method == 'POST':  #this block is only entered when the form is submitted
        language = request.form.get('language')
        framework = request.form['framework']

        return '''<h1>The language value is: {}</h1>
                  <h1>The framework value is: {}</h1>'''.format(language, framework)

    return '''<form method="POST">
                  Language: <input type="text" name="language"><br>
                  Framework: <input type="text" name="framework"><br>
                  <input type="submit" value="Submit"><br>
              </form>'''

JSON Data

@app.route('/json-example', methods=['POST']) #GET requests will be blocked
def json_example():
    req_data = request.get_json()

    language = req_data['language']
    framework = req_data['framework']
    python_version = req_data['version_info']['python'] #two keys are needed because of the nested object
    example = req_data['examples'][0] #an index is needed because of the array
    boolean_test = req_data['boolean_test']

    return '''
           The language value is: {}
           The framework value is: {}
           The Python version is: {}
           The item at index 0 in the example list is: {}
           The boolean value is: {}'''.format(language, framework, python_version, example, boolean_test)

References
https://www.digitalocean.com/community/tutorials/processing-incoming-request-data-in-flask

from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/api/get-json')
def hello():
    return jsonify(hello='world') # Returns HTTP Response with {"hello": "world"}

person = {'name': 'Alice', 'birth-year': 1986}
return jsonify(person)

@app.route("/")
def index():
    return flask.jsonify(response_value_1=1,response_value_2="value")

References
https://riptutorial.com/flask/example/5831/return-a-json-response-from-flask-api
https://www.kite.com/python/answers/how-to-return-a-json-response-using-flask-in-python