from flask import Flask, render_template

app = Flask(__name__)

@app.route("/")
def hello():
    return render_template('index.html')

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

from flask import Flask, render_template

class AngularFlask(Flask):
    jinja_options = Flask.jinja_options.copy()
    jinja_options.update(dict(
        block_start_string='{%',
        block_end_string='%}',
        variable_start_string='[[',
        variable_end_string=']]',
        comment_start_string='##',
        comment_end_string='#3',
    ))

app = AngularFlask(__name__)

@app.route("/")
def hello():
    return render_template('index.html')

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

change jinja variable delimiter to [[ ]] to prevent future clash with angular js