j2prompt-lint/jinja2-prompt-template-corpus huggingface dataset:
{% for message in messages %}{% if loop.first and messages[0]['role'] != 'system' %}{{ '
system
You are a helpful assistant.

' }}{% endif %}{{'
' + message['role'] + '
' + message['content'] + '
' + '
'}}{% endfor %}{% if add_generation_prompt %}{{ '
assistant
' }}{% endif %}
{% for message in messages %}{% if message['role'] == 'user' %}{{ '
' + message['content'] + eos_token }}{% elif message['role'] == 'system' %}{{ raise_exception('System role not supported') }}{% elif message['role'] == 'assistant' %}{{ '
'  + message['content'] + eos_token }}{% endif %}{% if loop.last and add_generation_prompt %}{{ '
' }}{% endif %}{% endfor %}
{%- if messages[0]['role'] == 'system' %}
    {%- set system_message = messages[0]['content'] %}
    {%- set loop_messages = messages[1:] %}
{%- else %}
    {%- set loop_messages = messages %}
{%- endif %}

{{- bos_token }}
{%- for message in loop_messages %}
    {%- if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}
        {{- raise_exception('After the optional system message, conversation roles must alternate user/assistant/user/assistant/...') }}
    {%- endif %}
    {%- if message['role'] == 'user' %}
        {%- if loop.first and system_message is defined %}
            {{- ' 
 ' + system_message + '\n\n' + message['content'] + ' 
' }}
        {%- else %}
            {{- ' 
 ' + message['content'] + ' 
' }}
        {%- endif %}
    {%- elif message['role'] == 'assistant' %}
        {{- ' ' + message['content'] + eos_token}}
    {%- else %}
        {{- raise_exception('Only user and assistant roles are supported, with the exception of an initial optional system message!') }}
    {%- endif %}
{%- endfor %}