jinja2 how to remove trailing newline

Question

I\'m using jinja 2 to output a yaml file but can\'t seem to get rid of a trailing newline and the end of a for loop. Eg the below

 - request:
        path: {{ p         


        

Answer 1

Change your loop to strip white spaces from the top AND bottom of the output (notice extra "-" at the for loop close):

 {% for key, value in querystring.items() -%}
      {{ key }}: '{{ value }}'
 {%- endfor %}

In my tests (using https://github.com/abourguignon/jinja2-live-parser), the "-" must come after the first {%, not before the last to achieve what you're asking for.

Docs: http://jinja.pocoo.org/docs/dev/templates/#whitespace-control

Answer 2

I think you can get rid of it using the whitespace control feature. Thus I would modify the endfor block to {% endfor -%}

See if that does it!

Answer 3

The accepted answer is only half of the solution, because it removes all newlines.

You can avoid the trailing newline by first removing all newlines (using the minus signs at -%} and {%- in the for loop), and then inserting the desired newlines at the right place (using the loop.last condition).

The following templates renders a dictionary, d, to as JSON text:

{
    {% for key, value in d.items() -%}
    "{{ key }}": "{{ value }}"{{ ",
    " if not loop.last }}
    {%- endfor %}
}

For d = {'a':'1', 'b':'2'}, the template renders to

{
    "a": "1",
    "b": "2"
}

Answer 4

You can suppress rendering of the below lines:

<% for ... %>
<% endfor %>
<% if ... %>
<% endif %>

by setting trim_blocks=True and lstrip_blocks=True in your jinja2 environment. See the example below, info from their docs

context = {'querystring': querystring, 'path': path, 'content': content}    
jinja_env = jinja2.Environment(loader=jinja2.FileSystemLoader('templates/'), trim_blocks=True, lstrip_blocks=True)
print(jinja_env.get_template('my_template.yaml').render(context))

Answer 5

For those using Flask who arrive here, these lines did the trick for me:

app = Flask(__name__)
app.jinja_env.lstrip_blocks = True
app.jinja_env.trim_blocks = True

Answer 6

I found a way to solve this problem:

- request:
    path: {{ path }}
    headers:
      origin: 'somedomain.com'
      user-agent: 'agent'
      referer: 'some.domain.com'
      authority: 'somedomain.com'
    querystring: >-
      {% for key, value in querystring.items() -%}
      {{ key }}: '{{ value }}'
      {% endfor %}
  response:
    content:
      file: {{ content }}

• >, |: "clip": keep the line feed, remove the trailing blank lines.
• >-, |=: "strip": remove the line feed, remove the trailing blank lines.
• >+, |+: "keep": keep the line feed, keep trailing blank lines.

Thx Steve Bennett's post: In YAML, how do I break a string over multiple lines?