Django snippets

# number_human.py


from django.template import Library, Node


register = Library()

@register.simple_tag
def number_human(value, separator=',', precision=2, delimeter_count=3, decimal_separator='.'):
    """ Converts an integer or floating-point number or a string to a string
        containing the delimiter character (default comma)
        after every delimeter_count digits (by default 3 digits).

        For example:
            {% load number_human %}
            String: {% number_human '1234567890.5' ' ' %}
            Float: {% number_human 1234567890.5 ' ' %}
            Integer {% number_human 1234567890 ' ' %}

            String: {% number_human '1234567890,5' ' ' 1 3 ',' %}
    """
    f = ''
    if isinstance(value, float):
        negative = value < 0
        s = '%s.%df' % ('%', precision) % (abs(value))
        p = s.find(decimal_separator)
        if p > -1:
            f = s[p:]
            s = s[:p]
    elif isinstance(value, int):
        negative = value < 0
        s = str(abs(value))
    else:
        negative = False
        s = value
        p = s.find(decimal_separator)
        if p > -1:
            f = s[p:p + precision + 1]
            if f == decimal_separator:
                f = ''
            s = s[:p]

    groups = []
    while s:
        groups.insert(0, s[-delimeter_count:])
        s = s[:-delimeter_count]

    return '%s%s%s' % ('-' if negative else '', separator.join(groups), f)


# tests.py


from django.test import TestCase
from django import template


class NumberHumanTest(TestCase):
    def setUp(self):
        self.context = template.Context()

    def test_number_human(self):
        template_content = "{% load number_human %}[{% number_human '1234567890.5' ' ' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890.5]')

        template_content = "{% load number_human %}[{% number_human 1234567890.5 ' ' 1 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890.5]')

        template_content = "{% load number_human %}[{% number_human 123456789.5 ' ' 1 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[123 456 789.5]')

        template_content = "{% load number_human %}[{% number_human 12345678.5 ' ' 1 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[12 345 678.5]')

        template_content = "{% load number_human %}[{% number_human 1234567.5 ' ' 1 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567.5]')

        template_content = "{% load number_human %}[{% number_human 1234567890 ' ' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890]')

        template_content = "{% load number_human %}[{% number_human 123456789 ' ' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[123 456 789]')

        template_content = "{% load number_human %}[{% number_human 12345678 ' ' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[12 345 678]')

        template_content = "{% load number_human %}[{% number_human 1234567 ' ' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567]')

        template_content = "{% load number_human %}[{% number_human 1234567890.1234567890 ' ' 6 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890.123457]')

        template_content = "{% load number_human %}[{% number_human '1234567890.1234567890' ' ' 10 %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890.1234567890]')

        template_content = "{% load number_human %}[{% number_human '1234567890,1234567890' ' ' 10 3 ',' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890,1234567890]')

        template_content = "{% load number_human %}[{% number_human '1234567890,1234567890' ' ' 10 3 ',' %}]"
        value = template.Template(template_content).render(self.context)
        self.assertEqual(value, '[1 234 567 890,1234567890]')