Merge pull request #19 from Shopify/add-properties-and-replace

Add lower and upper properties and replace method which works similarly to date.replace

pyinter/interval.py

@@ -84,6 +84,8 @@ class Interval(object):
 
     lower_value = property(fget=lambda self: self._lower_value, doc='This intervals lower value')
     upper_value = property(fget=lambda self: self._upper_value, doc='This intervals upper value')
+    lower = property(fget=lambda self: self._lower, doc='Whether lower is Interval.OPEN or Interval.CLOSED')
+    upper = property(fget=lambda self: self._upper, doc='Whether upper is Interval.OPEN or Interval.CLOSED')
 
     def __init__(self, lower, lower_value, upper_value, upper):
         """Create a new :class:`~pyinter.Interval` object, lower and upper should be one of
@@ -100,6 +102,20 @@ def copy(self):
         """Returns a new :class:`~pyinter.Interval` object with the same bounds and values."""
         return Interval(self._lower, self._lower_value, self._upper_value, self._upper)
 
+    def replace(self, lower=None, lower_value=None, upper_value=None, upper=None):
+        interval = self.copy()
+
+        if lower is not None:
+            interval._lower = lower
+        if lower_value is not None:
+            interval._lower_value = lower_value
+        if upper_value is not None:
+            interval._upper_value = upper_value
+        if upper is not None:
+            interval._upper = upper
+
+        return interval
+
     def __repr__(self):
         lower_string = '(' if self._lower == self.OPEN else '['
         upper_string = ')' if self._upper == self.OPEN else ']'

tests/test_interval.py

@@ -17,6 +17,13 @@ def test_interval_copy_returns_a_new_instance():
     assert one is not one.copy()
 
 
+def test_replace():
+    assert i.open(1, 4).replace(upper_value=5) == i.open(1, 5)
+    assert i.open(1, 4).replace(upper=i.Interval.CLOSED) == i.openclosed(1, 4)
+    assert i.open(1, 4).replace(lower=i.Interval.CLOSED) == i.closedopen(1, 4)
+    assert i.open(1, 4).replace(lower_value=0) == i.open(0, 4)
+
+
 def test_overlaps():
     assert i.open(1, 4).overlaps(i.open(3, 6))
     assert i.open(3, 6).overlaps(i.open(1, 4))

tests/test_interval_construction.py

@@ -7,10 +7,10 @@ def test_open_interval_construction():
     expected_upper_value = 100
     expected_upper = i.Interval.OPEN
     result = i.Interval(i.Interval.OPEN, 10, 100, i.Interval.OPEN)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_closed_interval_construction():
@@ -19,10 +19,10 @@ def test_closed_interval_construction():
     expected_upper_value = 100
     expected_upper = i.Interval.CLOSED
     result = i.Interval(i.Interval.CLOSED, 10, 100, i.Interval.CLOSED)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_openclosed_interval_construction():
@@ -31,10 +31,10 @@ def test_openclosed_interval_construction():
     expected_upper_value = 100
     expected_upper = i.Interval.CLOSED
     result = i.Interval(i.Interval.OPEN, 10, 100, i.Interval.CLOSED)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_closedopen_interval_construction():
@@ -43,10 +43,10 @@ def test_closedopen_interval_construction():
     expected_upper_value = 100
     expected_upper = i.Interval.OPEN
     result = i.Interval(i.Interval.CLOSED, 10, 100, i.Interval.OPEN)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_open_interval_construction_using_helper():
@@ -55,10 +55,10 @@ def test_open_interval_construction_using_helper():
     expected_upper_value = 100
     expected_upper = i.Interval.OPEN
     result = i.open(10, 100)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_closed_interval_construction_using_helper():
@@ -67,21 +67,21 @@ def test_closed_interval_construction_using_helper():
     expected_upper_value = 100
     expected_upper = i.Interval.CLOSED
     result = i.closed(10, 100)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 def test_openclosed_interval_construction_using_helper():
     expected_lower = i.Interval.OPEN
     expectedlower_value = 10
     expected_upper_value = 100
     expected_upper = i.Interval.CLOSED
     result = i.openclosed(10, 100)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper
 
 
 def test_closedopen_interval_construction_using_helper():
@@ -90,7 +90,7 @@ def test_closedopen_interval_construction_using_helper():
     expected_upper_value = 100
     expected_upper = i.Interval.OPEN
     result = i.closedopen(10, 100)
-    assert result._lower == expected_lower
+    assert result.lower == expected_lower
     assert result.lower_value == expectedlower_value
-    assert result._upper_value == expected_upper_value
-    assert result._upper == expected_upper
+    assert result.upper_value == expected_upper_value
+    assert result.upper == expected_upper