How to convert string to uppercase / lowercase in Jinja2?

问题

I am trying to convert to upper case a string in a Jinja template I am working on.

In the template documentation, I read:

upper(s)
    Convert a value to uppercase.

So I wrote this code:

{% if student.department == "Academy" %}
    Academy
{% elif  upper(student.department) != "MATHS DEPARTMENT" %}
    Maths department
{% endif %}

But I am getting this error:

UndefinedError: 'upper' is undefined

So, how do you convert a string to uppercase in Jinja2?

回答1:

Filters are used with the |filter syntax:

{% elif  student.department|upper != "MATHS DEPARTMENT" %}
    Maths department
{% endif %}

or you can use the str.upper() method:

{% elif  student.department.upper() != "MATHS DEPARTMENT" %}
    Maths department
{% endif %}

Jinja syntax is Python-like, not actual Python. :-)

回答2:

And you can use: Filter like this

{% filter upper %}
    UPPERCASE
{% endfilter %}

来源：https://stackoverflow.com/questions/23195321/how-to-convert-string-to-uppercase-lowercase-in-jinja2