Merge pull request #606 from qutech/issues/604_expression_repr

Fix expression repr

changes.d/604.bugfix

@@ -0,0 +1 @@
+Fix `repr` of `ExpressionScalar` when constructed from a sympy expression. Also replace `Expression` with `ExpressionScalar` in `repr`.

qupulse/expressions.py

@@ -265,7 +265,10 @@ def __str__(self) -> str:
         return str(self._sympified_expression)
 
     def __repr__(self) -> str:
-        return 'Expression({})'.format(repr(self._original_expression))
+        if self._original_expression is None:
+            return f"ExpressionScalar('{self._sympified_expression!r}')"
+        else:
+            return f"ExpressionScalar({self._original_expression!r})"
 
     def __format__(self, format_spec):
         if format_spec == '':

tests/expression_tests.py

@@ -2,6 +2,7 @@
 import sys
 
 import numpy as np
+import sympy.abc
 from sympy import sympify, Eq
 
 from qupulse.expressions import Expression, ExpressionVariableMissingException, NonNumericEvaluation, ExpressionScalar, ExpressionVector
@@ -257,7 +258,23 @@ def test_evaluate_variable_missing(self) -> None:
     def test_repr(self):
         s = 'a    *    b'
         e = ExpressionScalar(s)
-        self.assertEqual("Expression('a    *    b')", repr(e))
+        self.assertEqual("ExpressionScalar('a    *    b')", repr(e))
+
+    def test_repr_original_expression_is_sympy(self):
+        # in this case we test that we get the original expression back if we do
+        # eval(repr(e))
+
+        org = sympy.sympify(3.1415)
+        e = ExpressionScalar(org)
+        self.assertEqual(e, eval(repr(e)))
+
+        org = sympy.abc.a * sympy.abc.b
+        e = ExpressionScalar(org)
+        self.assertEqual(e, eval(repr(e)))
+
+        org = sympy.sympify('3/17')
+        e = ExpressionScalar(org)
+        self.assertEqual(e, eval(repr(e)))
 
     def test_str(self):
         s = 'a    *    b'

tests/pulses/arithmetic_pulse_template_tests.py

@@ -533,7 +533,7 @@ def test_repr(self):
 
         with mock.patch.object(DummyPulseTemplate, '__repr__', wraps=lambda *args: 'dummy'):
             r = repr(ArithmeticPulseTemplate(pt, '-', scalar))
-        self.assertEqual("(dummy - Expression('x'))", r)
+        self.assertEqual("(dummy - ExpressionScalar('x'))", r)
 
         arith = ArithmeticPulseTemplate(pt, '-', scalar, identifier='id')
         self.assertEqual(super(ArithmeticPulseTemplate, arith).__repr__(), repr(arith))