for-in-if in jinja2 throws exception

Question

I am new to both Python and Jinja2. I'd like to read a value in a dictionary of a list. I think there is an answer for such operation here. Unfortunately this does not seem to work in Jinja2. I get this:

jinja2.exceptions.TemplateSyntaxError: Encountered unknown tag 'item'.

From what I know Jinja2 does not comprehend full Python, which I think is at the heart of the problem here. Can anyone please confirm?

Can anyone please confirm? maybe, if you would share the code that raises this error.. — Tim

Randomazer Randomazer · Accepted Answer · 2015-10-08T19:56:31

Example using Flask:

main.py

from flask import Flask, render_template

app = Flask(__name__)

@app.route('/')
def hello_world():
    dicts = [
        { "name": "Tom", "age": 10 },
        { "name": "Mark", "age": 5 },
        { "name": "Pam", "age": 7 },
        { "name": "Dick", "age": 12 }
    ]
    return render_template("test.html", dicts = dicts)

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

In folder templates

test.html

<html>
<head>
<table>
   <tr>
    <th>Name</th>
    <th>Age</th>
   </tr>
{% for dic in dicts %}
    {%if dic['name'] == 'Pam'%}
        <tr><td><b>{{dic['name']}}</b></td><td><b>{{dic['age']}}</b></td></tr>
    {%else%}
        <tr><td>{{dic['name']}}</td><td>{{dic['age']}}</td></tr>
    {%endif%}
{% endfor %}
</table>
</body>
</html>

Output:

for-in-if in jinja2 throws exception

1 Answers