Is there a direct approach to format numbers in jinja2?

Question

I need to format decimal numbers in jinja2.

When I need to format dates, I call the strftime() method in my template, like this:

{{ somedate.strftime('%Y-%m-%d') }}

I wonder if there is a similar approach to do this over numbers.

Thanks in advance!

can you not do `{{ "{0:0.2f}".format(my_num) }}` or `{{ my_num|format "%0.2f" }}` (http://wsgiarea.pocoo.org/jinja/docs/filters.html#format) — Joran Beasley, Oct 01 '12 at 21:07
thanks Joran. The first suggestion works OK, but doing this: {{ my_num|format "%0.2f" }} gives a exception. — Lucas, Oct 01 '12 at 21:28
@Lucas The example with the filter in @JoranBeasley's comment is back-to-front; it should be `"%0.2f" | format(my_num)`. See http://jinja.pocoo.org/docs/dev/templates/#format — Sam, Jul 27 '16 at 09:43

Lipis · Accepted Answer · 2013-06-03T13:58:02.463

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You can do it simply like this, the Python way:

{{ '%04d' % 42 }}

{{ 'Number: %d' % variable }}

Or using that method:

{{ '%d' | format(42) }}

I personally prefer the first one since it's exactly like in Python.

edited Jun 03 '13 at 13:58

answered Oct 01 '12 at 21:12

Lipis

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cept that method of string format is depreciated and should be avoided when possible (I guess ... or something like that...) – Joran Beasley Oct 01 '12 at 21:16
@JoranBeasley either case it's not deprecated in the latest version 2.7 on GAE and in the next couple of years I don't see any plans from Google to switch on version 3.0.. It will take some time :) – Lipis Oct 01 '12 at 21:26
I agree I've just gotten flak for using that method instead of the other method ... just mentioning it ... wasnt saying your answer was wrong at all(at least thats not what I meant)... – Joran Beasley Oct 01 '12 at 21:45
@JoranBeasley You're right for the new format though.. and I totally hate it :( – Lipis Oct 01 '12 at 21:48
poor readability – Fabien Snauwaert Jul 19 '22 at 14:41

score 44 · Answer 2 · answered May 04 '14 at 01:47

I want to highlight Joran Beasley's comment because I find it the best solution:

Original comment:

can you not do {{ "{0:0.2f}".format(my_num) }} or {{ my_num|format "%0.2f" }} (wsgiarea.pocoo.org/jinja/docs/filters.html#format) – Joran Beasley Oct 1 '12 at 21:07`

Indeed, {{ '{0:0.2f}'.format(100) }} works fantastically.

This is just python string formatting. Given the first argument, {0}, format it with the following format 0.2f.

score 11 · Answer 3 · answered Oct 01 '12 at 21:17

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You could use round it will let you round the number to a given precision usage is:

 round(value, precision=0, method='common')

The first parameter specifies the precision (default is 0), the second the rounding method from which you can choose 3:

'common' rounds either up or down
'ceil' always rounds up
'floor' always rounds down

answered Oct 01 '12 at 21:17

Tkingovr

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Or `some_number|round(precision=2, method='common')` – Fabien Snauwaert Jul 19 '22 at 14:43

score 6 · Answer 4 · answered Mar 28 '15 at 02:12

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Formatting and padding works well in the same way.

{{ "{0}".format(size).rjust(15) }}

answered Mar 28 '15 at 02:12

Sandip Bhattacharya

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score 1 · Answer 5 · answered Jul 19 '22 at 16:33

I know the OP says 'direct' but after a good hour wasted on this I personally came to this conclusion: 'direct' solutions for printing numbers in Jinja2 are either:

hard to read (if you don't code in Python every day all day);
or do stuff you may not necessarily want (e.g. drop trailing zeros.)

Ended up with this which is short and gives me code that's easy to read:

@app.template_filter()
def two_decimals_rounded_up(value):
    """
    Filter to always print with two decimals, rounded up.

    We need this because:
    - The built-in `round` filter provided by Jinja2 will drop trailing zeros.
      e.g. `|round(precision=2, method='ceil')`
    - String formatting in Python is fucking unreadable.

    On rounding up: https://stackoverflow.com/a/9232310/1717535
    """
    return '{0:.2f}'.format(math.ceil(value * 100.0) / 100.0)

And then in the template:

{{ duration|two_decimals_rounded_up }}

Is there a direct approach to format numbers in jinja2?

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