Feat: set_render to tex for module import and to txt in doctest

mapytex/calculus/API/tokens/__init__.py

@@ -19,6 +19,8 @@ from decimal import Decimal as _Decimal
 from .number import Integer, Decimal, Fraction
 from .polynomial import Polynomial, Linear, Quadratic
 
+from .token import Token
+
 __all__ = ["factory"]
 
 

mapytex/calculus/API/tokens/token.py

@@ -29,6 +29,15 @@ class Token(object):
     def random(cls):
         raise NotImplemented
 
+
+    @classmethod
+    def set_render(cls, render):
+        """ Define default render function
+
+        :param render: render name (txt or tex)
+        """
+        cls.RENDER = render
+
     def explain(self):
         """ Yield every calculus step which have lead to self