json.dumps return invalid json in flask view-CodePudding

I have a simple code:

products_list: list = [{"product_name": "product #1"}, {"product_name": "product #2"}]
return render_template('index.html', data=json.dumps(products_list))

My index template:

<body>
    <script>
        console.log({{ data }});
    </script>
</body>

But on the page i get an invalid json with &#34, #1&#34 characters.

 console.log([{&#34;product_name&#34;: &#34;product #1&#34;}, {&#34;product_name&#34;: &#34;product #2&#34;}]);

Why it happens?

CodePudding user response：

The problem here is that flask is escaping the quotes in your JSON by replacing them with ". You can disable this by adding the |safe filter to your template.

So your HTML will be:

<body>
    <script>
        console.log({{ data|safe }});
    </script>
</body>

Related Question

CodePudding user response：

return render_template('index.html', data=json.dumps(products_list))

should be:

return render_template('index.html', data=json.loads(products_list))

json.loads takes a string and converts it into JSON object. json.dumps takes a JSON object and converts it into string.

>>> import json
>>> s = '[{"product_name": "product #1"}, {"product_name": "product #2"}]'
>>> json.dumps(s)
'"[{\\"product_name\\": \\"product #1\\"}, {\\"product_name\\": \\"product #2\\"}]"'
>>> json.loads(s)
[{'product_name': 'product #1'}, {'product_name': 'product #2'}]
>>> json.dumps(json.loads(s))
'[{"product_name": "product #1"}, {"product_name": "product #2"}]'

" is the escape code for " character.

CodePudding user response：

Change your code like below code:

return render_template('index.html', data=json.dumps(products_list[0]))