se adiciona extensions para la dian

FossilOrigin-Name: f5521ddbfb903915de88a26ba5197b67efa1ebfd66337061ee9e3653c59dd217

facho/model/fields/amount.py

@@ -0,0 +1,31 @@
+from .field import Field
+from collections import defaultdict
+import facho.fe.form as form
+
+class Amount(Field):
+    def __init__(self, name=None, default=None, precision=6):
+        self.field_name = name
+        self.values = {}
+        self.default = default
+        self.precision = precision
+        
+    def __get__(self, model, cls):
+        if model is None:
+            return self
+        assert self.name is not None
+ 
+        self.__init_value(model)
+        model._set_field(self.name, self)
+        return self.values[model]
+
+    def __set__(self, model, value):
+        assert self.name is not None
+        self.__init_value(model)
+        model._set_field(self.name, self)
+        self.values[model] = form.Amount(value, precision=self.precision)
+
+        self._changed_field(model, self.name, value)
+
+    def __init_value(self, model):
+        if model not in self.values:
+            self.values[model] = form.Amount(self.default or 0)