numpy · mattip · Jun 4, 2020 · May 28, 2020 · May 29, 2020 · May 29, 2020
diff --git a/numpy/core/_dtype.py b/numpy/core/_dtype.py
@@ -24,11 +24,11 @@
 def _kind_name(dtype):
    try:
        return _kind_to_stem[dtype.kind]
-    except KeyError:
+    except KeyError as e:
        raise RuntimeError(
            "internal dtype error, unknown kind {!r}"
            .format(dtype.kind)
-        )
+        ) from None


 def __str__(dtype):

diff --git a/numpy/core/fromnumeric.py b/numpy/core/fromnumeric.py
@@ -536,9 +536,9 @@ def put(a, ind, v, mode='raise'):
    """
    try:
        put = a.put
-    except AttributeError:
+    except AttributeError as e:
        raise TypeError("argument 1 must be numpy.ndarray, "
-                        "not {name}".format(name=type(a).__name__))
+                        "not {name}".format(name=type(a).__name__)) from e

    return put(ind, v, mode=mode)


diff --git a/numpy/core/records.py b/numpy/core/records.py
@@ -461,8 +461,8 @@ def __getattribute__(self, attr):
        fielddict = ndarray.__getattribute__(self, 'dtype').fields
        try:
            res = fielddict[attr][:2]
-        except (TypeError, KeyError):
-            raise AttributeError("recarray has no attribute %s" % attr)
+        except (TypeError, KeyError) as e:
+            raise AttributeError("recarray has no attribute %s" % attr) from e
        obj = self.getfield(*res)

        # At this point obj will always be a recarray, since (see
@@ -509,8 +509,8 @@ def __setattr__(self, attr, val):
                    return ret
        try:
            res = fielddict[attr][:2]
-        except (TypeError, KeyError):
-            raise AttributeError("record array has no attribute %s" % attr)
+        except (TypeError, KeyError) as e:
+            raise AttributeError("record array has no attribute %s" % attr) from e
        return self.setfield(val, *res)

    def __getitem__(self, indx):

diff --git a/numpy/ctypeslib.py b/numpy/ctypeslib.py
@@ -297,8 +297,8 @@ def ndpointer(dtype=None, ndim=None, shape=None, flags=None):
        if num is None:
            try:
                flags = [x.strip().upper() for x in flags]
-            except Exception:
-                raise TypeError("invalid flags specification")
+            except Exception as e:
+                raise TypeError("invalid flags specification") from e
            num = _num_fromflags(flags)

    # normalize shape to an Optional[tuple]
@@ -377,10 +377,10 @@ def _ctype_from_dtype_scalar(dtype):
        dtype_native = dtype.newbyteorder('=')
        try:
            ctype = _scalar_type_map[dtype_native]
-        except KeyError:
+        except KeyError as e:
            raise NotImplementedError(
                "Converting {!r} to a ctypes type".format(dtype)
-            )
+            ) from None

        if dtype_with_endian.byteorder == '>':
            ctype = ctype.__ctype_be__