CODEWITHSUNDEEP
pythonjinja2
CppLearner
CppLearner

Reputation: 17040

Extra newline in Jinja2 template

Here is my Python code for generating the template

import jinja2

with open('test.j2', 'r') as f:
    template_body = f.read()

template = jinja2.Template(template_body)#, trim_blocks=True)
result = template.render(longest=len('staging'),
    envs=['devel', 'staging', 'prod'])

print(result)

The idea here is that I want to produce the follwing indented based on the longest string in the list.

devel   = 1
staging = 1
prod    = 1

I finally came up with a solution:

{% for env in envs -%}
{%- set padding = (longest - env|length + 1)|string %}
{% set f = "%-" + padding + "s" -%}
{{ env }}{{ f | format(' ',)}}= 1
{%- endfor %}

But I am getting

$ python test.py

devel   = 1
staging = 1
prod    = 1

There is an extra newline at the start of the output. Using Python's debugger, we can see the output:

$ python test.py
> /private/tmp/test.py(11)<module>()
-> print(result)
(Pdb) result
u'\ndevel   = 1\nstaging = 1\nprod    = 1'

Upvotes: 1

Views: 7927

Answers (1)

Amadan
Amadan

Reputation: 198438

You are printing a newline before each line by not suppressing the newline at the set line. On the other hand, you're suppressing a newline at the end in the endfor line. Thus, you get a newline before each line, but not after each line.

By changing the code like this, you get the reverse:

{% for env in envs -%}
{%- set padding = (longest - env|length + 1)|string -%}
{% set f = "%-" + padding + "s" -%}
{{ env }}{{ f | format(' ',)}}= 1
{% endfor %}

and result will be

u'devel   = 1\nstaging = 1\nprod    = 1\n'

Upvotes: 2

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