from django.template.defaultfilters import stringfilter
from django import template
register = template.Library()
@register.filter
@stringfilter
def sell_price(value):
    if self.sell_price.sell:
        if self.sell_price.sell.how_m:
            value.sell_price = self.sell_price.price-self.sell_price.sell.how_m
        elif self.sell_price.sell.how_p:
            value.sell_price = self.sell_price.price-((self.sell_price.price/100)*self.sell_price.sell.how_p)
    else:
        value.sell=0
    return value.sell_price()

from django.utils.html import conditional_escape
from django.utils.safestring import mark_safe
from things.models import Path, Margin, Sell, View, Tissue, Thing

@register.filter(needs_autoescape=True)
def price(id, autoescape=None):
	m3 = Thing.objects.get(id=id)
	price = m3.price
    if m3.sell.name_sell=="product_today":
        summa = m3.price+((m3.price/100)*m3.margin.how_mach + m3.margin.how_maney) - ((m3.price/100)*m3.sell.how_mach + m3.sell.how_maney)
    else:
        how_mach_sell = m3.name.sell.how_mach + m3.path.sell.how_mach + m3.tissue.sell.how_mach + m3.sell.how_mach
        how_maney_sell = m3.name.sell.how_maney + m3.path.sell.how_maney + m3.tissue.sell.how_maney + m3.sell.how_maney

        how_mach_margin = m3.name.margin.how_mach + m3.path.margin.how_mach + m3.tissue.margin.how_mach + m3.margin.how_mach
        how_maney_margin = m3.name.margin.how_maney + m3.path.margin.how_maney + m3.tissue.margin.how_maney + m3.margin.how_maney

        summa = (m3.price + ((m3.price/100)*how_mach_margin + how_maney_margin)) - ((m3.price/100)*how_mach_sell + how_maney_sell)
    result = '<font color="#990000"><strike>%s</strike></font><br>%s' % ((price), (summa))
    return mark_safe(result)

IndentationError at /
expected an indented block (sell.py, line 10)