Added unary inversion operator and tests for logical operations. Closes

#171

tests/test_methods_external.py

@@ -17,3 +17,23 @@ def test_moving_average_pandas_compatibility():
     assert all(pd_ts.index[i] == i for i in range(1, 9))
     assert np.isnan(pd_ts.values[0])
     assert all(pd_ts.values[i] == ts.mean(i - 1, i + 1) for i in range(2, 9))
+
+
+def test_moving_average_pandas_flag():
+    ts = traces.TimeSeries([[1, 2], [2, 3], [6, 1], [8, 4]], default=0)
+    ma = ts.moving_average(1, 2, -1, 11, pandas=True)
+    assert list(zip(ma.index, ma)) == [
+        (-1, 0.0),
+        (0, 0.0),
+        (1, 1.0),
+        (2, 2.5),
+        (3, 3.0),
+        (4, 3.0),
+        (5, 3.0),
+        (6, 2.0),
+        (7, 1.0),
+        (8, 2.5),
+        (9, 4.0),
+        (10, 4.0),
+        (11, 4.0),
+    ]

tests/test_operations.py

@@ -165,3 +165,33 @@ def test_to_bool_default():
     assert TimeSeries(data=data, default=None).to_bool(default=10).default == 10
     assert TimeSeries(data=data, default=0).to_bool(default=10).default == 10
     assert TimeSeries(data=data, default=5).to_bool(default=10).default == 10
+
+
+def test_truthiness():
+    data = [(0, 0), (2, 5), (3, 0), (4, 7), (10, 3)]
+    assert bool(TimeSeries()) is False
+    assert bool(TimeSeries(data=data)) is True
+
+    if TimeSeries():
+        assert "should not be here"
+
+
+def test_logical_operations():
+    ts1 = TimeSeries([(0, 0), (2, 5), (3, 0), (4, 7), (10, 3)])
+    ts2 = TimeSeries([(0, 0), (1, 1), (2, 3), (4, 0), (5, 5), (10, 1), (11, 0)])
+
+    a_or = [(0, 0), (1, 1), (2, 5), (3, 3), (4, 7), (5, 7), (10, 3), (11, 3)]
+    assert list(ts1.logical_or(ts2).items()) == a_or
+    assert list((ts1 | ts2).items()) == a_or
+
+    a_and = [(0, 0), (1, 0), (2, 3), (3, 0), (4, 0), (5, 5), (10, 1), (11, 0)]
+    assert list(ts1.logical_and(ts2).items()) == a_and
+    assert list((ts1 & ts2).items()) == a_and
+
+    a_xor = [(0, 0), (1, 1), (2, 0), (3, 1), (4, 1), (5, 0), (10, 0), (11, 1)]
+    assert list(ts1.logical_xor(ts2).items()) == a_xor
+    assert list((ts1 ^ ts2).items()) == a_xor
+
+    a_not = [(0, True), (2, False), (3, True), (4, False), (10, False)]
+    assert list(ts1.to_bool(invert=True).items()) == a_not
+    assert list((~ts1).items()) == a_not

tests/test_traces.py

@@ -244,3 +244,15 @@ def test_set_same_interval_twice():
 
     tr[17:42] = 0
     assert list(tr.items()) == [(0, 10), (17, 0), (42, 10), (100, 10)]
+
+
+def test_convenience_access_methods():
+    ts = TimeSeries([(1, 2), (2, 3), (6, 1), (8, 4)])
+    assert ts.first_key() == 1
+    assert ts.first_value() == 2
+    assert ts.first_item() == (1, 2)
+    assert ts.last_key() == 8
+    assert ts.last_value() == 4
+    assert ts.last_item() == (8, 4)
+    assert ts.get_item_by_index(0) == (1, 2)
+    assert ts.get_item_by_index(-1) == (8, 4)

traces/timeseries.py

@@ -112,11 +112,10 @@ def _get_previous(self, time):
             return left_value
         elif right_index == 0:
             return self.default
-        else:
+        else:  # pragma: no cover
             msg = (
                 f"self._d.bisect_right({time}) returned a negative value. "
-                """This "can't" happen: please file an issue at """
-                "https://github.com/datascopeanalytics/traces/issues"
+                """This "can't" happen: please help by filing an issue."""
             )
             raise ValueError(msg)
 
@@ -1008,6 +1007,10 @@ def __xor__(self, other):
         """Allow a ^ b syntax"""
         return self.logical_xor(other)
 
+    def __invert__(self):
+        """Allow ~a syntax"""
+        return self.to_bool(invert=True)
+
     def __eq__(self, other):
         return self.items() == other.items()