Python flask-cors ImportError: No module named 'flask-cors' Raspberry pi

I'm following the flask-cors tutorial from the documentation here: https://pypi.python.org/pypi/Flask-Cors

but when i installed it on my raspberry pi and run my python app i'm getting this error

Traceback (most recent call last): File "app.py", line 3, in <module> from flask_cors import CORS, cross_origin ImportError: No module named 'flask_cors'

here is my python script:

from flask import Flask
from Main import main
from flask_cors import CORS, cross_origin    
app = Flask(__name__)
CORS(app)
main = main() 

@app.route('/turn' ,methods=['GET', 'OPTIONS'])
def index():
  return main.turn()

if __name__ == '__main__': 
  app.run(debug=True, host='0.0.0.0')

If you import sys and print(sys.path), this will show you where your available packages are installed.

In the event that pip installed flask_cors outside of one of these directories, you should move the file to one of the directories or you can sys.path.append(<your path to flask_cors>).

To prevent pip from installing into a bad directory, I would recommend this answer

It worked for me finally