tytk tytk - 3 months ago 24
Python Question

How to get values from dictionary in jinja when key is a variable?

I'm trying to retrieve entries from a python dictionary in jinja2, but the problem is I don't know what key I want to access ahead of time - the key is stored in a variable called

s.course
. So my problem is I need to double-substitute this variable. I don't want to use a
for
loop because that will go through the dictionary way more than is necessary. Here's a workaround that I created, but it's possible that the
s.course
values could change so obviously hard-coding them like this is bad. I want it to work essentially like this:

{% if s.course == "p11" %}
{{course_codes.p11}}
{% elif s.course == "m12a" %}
{{course_codes.m12a}}
{% elif s.course == "m12b" %}
{{course_codes.m12b}}
{% endif %}


But I want it to look like this:

{{course_codes.{{s.course}}}}


Thanks!

Answer

You can use course_codes.get(s.course):

>>> import jinja2
>>> env = jinja2.Environment()
>>> t = env.from_string('{{ codes.get(mycode) }}')
>>> t.generate(codes={'a': '123'}, mycode='a').next()
u'123'
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