package/python-sympy: new package

SymPy is a Python library for symbolic mathematics. It aims
to become a full-featured computer algebra system (CAS)
while keeping the code as simple as possible in order to be
comprehensible and easily extensible. SymPy is written
entirely in Python.

https://www.sympy.org/

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

support/testing/tests/package/sample_python_sympy.py

@@ -0,0 +1,15 @@
+#! /usr/bin/env python3
+
+from sympy import symbols, expand, factor
+
+x, y = symbols('x y')
+
+expr = x + 2*y
+
+expanded_expr = expand(x*expr)
+print(expanded_expr)
+assert str(expanded_expr) == "x**2 + 2*x*y"
+
+factored_expr = factor(expanded_expr)
+print(factored_expr)
+assert str(factored_expr) == "x*(x + 2*y)"