Fix related gist (Step 6: Setting up Flask)

[d2718nis]

What's wrong

@dvf it would be great if you could fix Step 6: Setting up Flask gist, it affects the workflow at the Learn Blockchains by Building One article. Also there is no way to mention someone at the gist comments, so I created this issue instead.

Expected behavior

full_chain endpoint should return JSON:

{
  "chain": [
    {
      "index": 1, 
      "previous_hash": 1, 
      "proof": 100, 
      "timestamp": 1532563934.4369285, 
      "transactions": []
    }
  ], 
  "length": 1
}

Actual behavior

NameError raised while trying to access the full_chain endpoint:

Traceback (most recent call last):
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 2309, in __call__        
    return self.wsgi_app(environ, start_response)
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 2295, in wsgi_app        
    response = self.handle_exception(e)
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/_compat.py", line 35, in reraise       
    raise value
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 2292, in wsgi_app        
    response = self.full_dispatch_request()
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/_compat.py", line 35, in reraise       
    raise value
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "~/blockchain/.venv/lib/python3.6/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "~/blockchain/blockchain.py", line 132, in full_chain                                        
    return jsonify(response), 200
NameError: name 'jsonify' is not defined

Solution

Fix imports here, replace from flask import Flask with from flask import Flask, jsonify

[dvf]

Thanks for this!