Add missing _print_Exp1 function to theanocode printer

sympy/printing/tests/test_theanocode.py

@@ -611,3 +611,22 @@ def test_complexfunctions():
 def test_constantfunctions():
     tf = theano_function([],[1+1j])
     assert(tf()==1+1j)
+
+
+def test_Exp1():
+    """
+    Test that exp(1) prints without error and evaluates close to sympy's E
+    """
+    # sy.exp(1) should yield same instance of E as sy.E (singleton), but extra
+    # check added for sanity
+    e_a = sy.exp(1)
+    e_b = sy.E
+
+    np.testing.assert_allclose(float(e_a), np.e)
+    np.testing.assert_allclose(float(e_b), np.e)
+
+    e = theano_code_(e_a)
+    np.testing.assert_allclose(float(e_a), e.eval())
+
+    e = theano_code_(e_b)
+    np.testing.assert_allclose(float(e_b), e.eval())

sympy/printing/theanocode.py

@@ -215,6 +215,9 @@ def _print_slice(self, expr, **kwargs):
     def _print_Pi(self, expr, **kwargs):
         return 3.141592653589793
 
+    def _print_Exp1(self, expr, **kwargs):
+        return ts.exp(1)
+
     def _print_Piecewise(self, expr, **kwargs):
         import numpy as np
         e, cond = expr.args[0].args  # First condition and corresponding value