For these template tags, we will be using the simple_tag decorator that parses the components and requires you to just define the rendering function, as follows:

1. First, let's add a helper method for putting together the query strings that each of our tags will output:

# utils/templatetags/utility_tags.py
from urllib.parse import urlencode

from django import template
from django.utils.encoding import force_str

register = template.Library()


def construct_query_string(context, query_params):
    # empty values will be removed
    query_string = context["request"].path
    if len(query_params):
        encoded_params = urlencode([
            (key, force_str(value))
            for (key, value) in query_params if value
        ]).replace("&", "&")
        query_string += f"?{encoded_params}"
    return query_string


"""TAGS"""
# ...

2. Then, we will create the {% modify_query %} template tag:

@register.simple_tag(takes_context=True)
def modify_query(context, *params_to_remove, **params_to_change):
    """Renders a link with modified current query parameters"""
    query_params = []
    get_data = context["request"].GET
    for key, last_value in get_data.items():
        value_list = get_data.getlist(key)
        if key not in params_to_remove:
            # don't add key-value pairs for params_to_remove
            if key in params_to_change:
                # update values for keys in params_to_change
                query_params.append((key, params_to_change[key]))
                params_to_change.pop(key)
            else:
                # leave existing parameters as they were
                # if not mentioned in the params_to_change
                for value in value_list:
                    query_params.append((key, value))
    # attach new params
    for key, value in params_to_change.items():
        query_params.append((key, value))
    return construct_query_string(context, query_params)

3. Next, let's create the {% add_to_query %} template tag:

@register.simple_tag(takes_context=True)
def add_to_query(context, *params_to_remove, **params_to_add):
    """Renders a link with modified current query parameters"""
    query_params = []
    # go through current query params..
    get_data = context["request"].GET
    for key, last_value in get_data.items():
        value_list = get_data.getlist(key)
        if key not in params_to_remove:
            # don't add key-value pairs which already
            # exist in the query
            if (key in params_to_add
                    and params_to_add[key] in value_list):
                params_to_add.pop(key)
            for value in value_list:
                query_params.append((key, value))
    # add the rest key-value pairs
    for key, value in params_to_add.items():
        query_params.append((key, value))
    return construct_query_string(context, query_params)

4. Lastly, let's create the {% remove_from_query %} template tag:

@register.simple_tag(takes_context=True)
def remove_from_query(context, *args, **kwargs):
    """Renders a link with modified current query parameters"""
    query_params = []
    # go through current query params..
    get_data = context["request"].GET
    for key, last_value in get_data.items():
        value_list = get_data.getlist(key)
        # skip keys mentioned in the args
        if key not in args:
            for value in value_list:
                # skip key-value pairs mentioned in kwargs
                if not (key in kwargs and
                        str(value) == str(kwargs[key])):
                    query_params.append((key, value))
    return construct_query_string(context, query_params)