Django提供了对模板中某些常用的设置常量的访问，比如settings。MEDIA_URL和一些语言设置，如果你使用django内置的通用视图或在render_to_response快捷函数中传入context实例关键字参数。以下是每种情况的示例:

from django.shortcuts import render_to_response
from django.template import RequestContext
from django.views.generic.simple import direct_to_template

def my_generic_view(request, template='my_template.html'):
    return direct_to_template(request, template)

def more_custom_view(request, template='my_template.html'):
    return render_to_response(template, {}, context_instance=RequestContext(request))

这些视图都有一些常用的设置，比如settings。模板可用的MEDIA_URL为{{MEDIA_URL}}，等等。

如果你在设置中寻找对其他常量的访问，那么只需将你想要的常量解包，并将它们添加到你在视图函数中使用的上下文字典中，如下所示:

from django.conf import settings
from django.shortcuts import render_to_response

def my_view_function(request, template='my_template.html'):
    context = {'favorite_color': settings.FAVORITE_COLOR}
    return render_to_response(template, context)

现在你可以访问设置了。在模板中使用{{FAVORITE_COLOR}}。

另一种方法是创建一个自定义模板标签，它可以让您从设置中获取值。

@register.tag
def value_from_settings(parser, token):
    try:
        # split_contents() knows not to split quoted strings.
        tag_name, var = token.split_contents()
    except ValueError:
        raise template.TemplateSyntaxError, "%r tag requires a single argument" % token.contents.split()[0]
    return ValueFromSettings(var)

class ValueFromSettings(template.Node):
    def __init__(self, var):
        self.arg = template.Variable(var)
    def render(self, context):        
        return settings.__getattr__(str(self.arg))

然后你可以使用:

{% value_from_settings "FQDN" %}

将它打印在任何页面上，而无需跳过上下文处理器的约束。

If we were to compare context vs. template tags on a single variable, then knowing the more efficient option could be benificial. However, you might be better off to dip into the settings only from templates that need that variable. In that case it doesn't make sense to pass the variable into all templates. But if you are sending the variable into a common template such as the base.html template, Then it would not matter as the base.html template is rendered on every request, so you can use either methods.

如果您决定使用template tags选项，那么使用下面的代码，因为它允许您传入一个默认值，以防有问题的变量未定义。

例如:get_from_settings my_variable as my_context_value

例如:get_from_settings my_variable my_default as my_context_value

class SettingsAttrNode(Node):
    def __init__(self, variable, default, as_value):
        self.variable = getattr(settings, variable, default)
        self.cxtname = as_value

    def render(self, context):
        context[self.cxtname] = self.variable
        return ''


def get_from_setting(parser, token):
    as_value = variable = default = ''
    bits = token.contents.split()
    if len(bits) == 4 and bits[2] == 'as':
        variable = bits[1]
        as_value = bits[3]
    elif len(bits) == 5 and bits[3] == 'as':
        variable     = bits[1]
        default  = bits[2]
        as_value = bits[4]
    else:
        raise TemplateSyntaxError, "usage: get_from_settings variable default as value " \
                "OR: get_from_settings variable as value"

    return SettingsAttrNode(variable=variable, default=default, as_value=as_value)

get_from_setting = register.tag(get_from_setting)

上面来自bchhun的例子很好，只是你需要从settings.py显式地构建上下文字典。下面是一个未经测试的示例，说明如何从settings.py的所有大写属性(re: "^[A-Z0-9_]+$")自动构建上下文字典。

在settings.py的末尾:

_context = {} 
local_context = locals()
for (k,v) in local_context.items():
    if re.search('^[A-Z0-9_]+$',k):
        _context[k] = str(v)

def settings_context(context):
    return _context

TEMPLATE_CONTEXT_PROCESSORS = (
...
'myproject.settings.settings_context',
...
)

如果有人像我一样发现了这个问题，那么我将发布我的解决方案，它适用于Django 2.0:

这个标记将一些settings.py变量值赋给模板的变量:

用法:{% get_settings_value template_var "SETTINGS_VAR" %}

应用程序/ templatetags / my_custom_tags.py:

from django import template
from django.conf import settings

register = template.Library()

class AssignNode(template.Node):
    def __init__(self, name, value):
        self.name = name
        self.value = value

    def render(self, context):
        context[self.name] = getattr(settings, self.value.resolve(context, True), "")
        return ''

@register.tag('get_settings_value')
def do_assign(parser, token):
    bits = token.split_contents()
    if len(bits) != 3:
        raise template.TemplateSyntaxError("'%s' tag takes two arguments" % bits[0])
    value = parser.compile_filter(bits[2])
    return AssignNode(bits[1], value)

你的模板:

{% load my_custom_tags %}

# Set local template variable:
{% get_settings_value settings_debug "DEBUG" %}

# Output settings_debug variable:
{{ settings_debug }}

# Use variable in if statement:
{% if settings_debug %}
... do something ...
{% else %}
... do other stuff ...
{% endif %}

查看Django如何创建自定义模板标签的文档:https://docs.djangoproject.com/en/2.0/howto/custom-template-tags/

Django提供了对模板中某些常用的设置常量的访问，比如settings。MEDIA_URL和一些语言设置，如果你使用django内置的通用视图或在render_to_response快捷函数中传入context实例关键字参数。以下是每种情况的示例:

from django.shortcuts import render_to_response
from django.template import RequestContext
from django.views.generic.simple import direct_to_template

def my_generic_view(request, template='my_template.html'):
    return direct_to_template(request, template)

def more_custom_view(request, template='my_template.html'):
    return render_to_response(template, {}, context_instance=RequestContext(request))

这些视图都有一些常用的设置，比如settings。模板可用的MEDIA_URL为{{MEDIA_URL}}，等等。

如果你在设置中寻找对其他常量的访问，那么只需将你想要的常量解包，并将它们添加到你在视图函数中使用的上下文字典中，如下所示:

from django.conf import settings
from django.shortcuts import render_to_response

def my_view_function(request, template='my_template.html'):
    context = {'favorite_color': settings.FAVORITE_COLOR}
    return render_to_response(template, context)

现在你可以访问设置了。在模板中使用{{FAVORITE_COLOR}}。