Added unit tests to ensure that the keyword is correctly used

Signed-off-by: nbonnin <[email protected]>

Author: naomi172839

pandas/tests/generic/test_generic.py

@@ -9,6 +9,7 @@
 from pandas import DataFrame, MultiIndex, Series, date_range
 import pandas.util.testing as tm
 
+
 # ----------------------------------------------------------------------
 # Generic types test cases
 
@@ -265,7 +266,6 @@ def test_metadata_propagation(self):
 
         # simple boolean
         for op in ["__eq__", "__le__", "__ge__"]:
-
             # this is a name matching op
             v1 = getattr(o, op)(o)
             v2 = getattr(o, op)(o2)
@@ -948,3 +948,20 @@ def test_axis_classmethods(self, box):
             assert obj._get_axis_number(v) == box._get_axis_number(v)
             assert obj._get_axis_name(v) == box._get_axis_name(v)
             assert obj._get_block_manager_axis(v) == box._get_block_manager_axis(v)
+
+    # Tests that the ignore keyword causes the intended functionality
+    def test_astype_ignores(self):
+        df = pd.DataFrame({"a": [1, 2, 3]})
+        df_validation = pd.DataFrame({"a": [1, 2, 3]})
+
+        # Tests that a KeyError is raised when raise is explicitly declared
+        with pytest.raises(KeyError):
+            df.astype({"b": str}, errors="raise")
+
+        # Tests that a KeyError is raised when no argument is declared
+        with pytest.raises(KeyError):
+            df.astype({"b": str})
+
+        # Tests that no KeyError is thrown if ignore is true.  Ensures there is no change to the initial DataFrame
+        df.astype({"b": str}, errors="ignore")
+        assert df.equals(df_validation)