add __truediv__ for AbstractPolynom

pymath/calculus/abstract_polynom.py

@@ -653,6 +653,35 @@ class AbstractPolynom(Explicable):
 
         return o_poly.__mul__(self)
 
+    def __truediv__(self, other):
+        r""" Overload /
+
+        >>> P = AbstractPolynom([1, 2, 4])
+        >>> P / 2
+        < AbstractPolynom x [< Fraction 1 / 2>, 1, 2]>
+        >>> for i in (P/2).explain():
+        ...    print(i)
+        ( 4 x^{  2 } + 2 x + 1 ) \times 2
+        \frac{ 4 }{ 2 } x^{  2 } + \frac{ 2 }{ 2 } x + \frac{ 1 }{ 2 }
+        2 x^{  2 } + x + \frac{ 1 }{ 2 }
+
+
+        """
+        ans_coefs = [Expression([c, other, op.div]) if c != 0
+                else 0
+                for c in self._coef
+                ]
+
+        ans = AbstractPolynom(ans_coefs, letter=self._letter)
+        ini_step = [Step(
+            self.postfix_tokens +
+            [other, op.mul]
+            )]
+
+        ans = ans.simplify()
+        ans.this_append_before(ini_step)
+        return ans
+
     @power_cache
     def __pow__(self, power):
         r""" Overload **