accept float for cpu

Signed-off-by: Ryan Lo <wenchih@apache.org>

flytekit/core/resources.py

@@ -13,7 +13,7 @@ class Resources(object):
 
         Resources(cpu="1", mem="2048")  # This is 1 CPU and 2 KB of memory
         Resources(cpu="100m", mem="2Gi")  # This is 1/10th of a CPU and 2 gigabytes of memory
-        Resources(cpu=2, mem=1024) # This is 2 CPU and 1 KB of memory
+        Resources(cpu=0.5, mem=1024) # This is 500m CPU and 1 KB of memory
 
         # For Kubernetes-based tasks, pods use ephemeral local storage for scratch space, caching, and for logs.
         # This allocates 1Gi of such local storage.
@@ -27,22 +27,28 @@ class Resources(object):
     Also refer to the `K8s conventions. <https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#resource-units-in-kubernetes>`__
     """
 
-    cpu: Optional[Union[str, int]] = None
+    cpu: Optional[Union[str, int, float]] = None
     mem: Optional[Union[str, int]] = None
     gpu: Optional[Union[str, int]] = None
     ephemeral_storage: Optional[Union[str, int]] = None
 
     def __post_init__(self):
-        def _check_none_or_str_or_int(value):
+        def _check_cpu(value):
+            if value is None:
+                return
+            if not isinstance(value, (str, int, float)):
+                raise AssertionError(f"{value} should be of type str or int or float")
+
+        def _check_others(value):
             if value is None:
                 return
             if not isinstance(value, (str, int)):
-                raise AssertionError(f"{value} should be a string or an integer")
+                raise AssertionError(f"{value} should be of type str or int")
 
-        _check_none_or_str_or_int(self.cpu)
-        _check_none_or_str_or_int(self.mem)
-        _check_none_or_str_or_int(self.gpu)
-        _check_none_or_str_or_int(self.ephemeral_storage)
+        _check_cpu(self.cpu)
+        _check_others(self.mem)
+        _check_others(self.gpu)
+        _check_others(self.ephemeral_storage)
 
 
 @dataclass

tests/flytekit/unit/core/test_resources.py

@@ -68,7 +68,7 @@ def test_convert_limits(resource_dict: Dict[str, str], expected_resource_name: _
 
 def test_incorrect_type_resources():
     with pytest.raises(AssertionError):
-        Resources(cpu=0.1)  # type: ignore
+        Resources(cpu=bytes(1))  # type: ignore
     with pytest.raises(AssertionError):
         Resources(mem=0.1)  # type: ignore
     with pytest.raises(AssertionError):