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Jinja2 template variable if None Object set a default value

How to make a variable in jijna2 default to "" if object is None instead of doing something like this?

      {% if p %}   
        {{ p.User['first_name']}}
      {% else %}
        NONE
      {%endif %}

So if object p is None I want to default the values of p (first_name and last_name) to "". Basically

nvl(p.User[first_name'], "")

Error receiving:

Error:  jinja2.exceptions.UndefinedError
    UndefinedError: 'None' has no attribute 'User'
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Use the none test (not to be confused with Python's None object!):

{% if p is not none %}   
    {{ p.User['first_name'] }}
{% else %}
    NONE
{% endif %}

or:

{{ p.User['first_name'] if p is not none else 'NONE' }}

or if you need an empty string:

{{ p.User['first_name'] if p is not none }}

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