refactor: array_library.py, update docstrings, add license

smallpebble/array_library.py

@@ -1,7 +1,21 @@
-"""Allows SmallPebble to dynamically switch between NumPy/CuPy,
-for its ndarray computations. The default is NumPy.
+# Copyright 2021 Sidney Radcliffe
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""Allows SmallPebble to dynamically switch between using NumPy/CuPy,
+as its ndarray library. The default is NumPy.
 
-Note to SmallPebble devs:
+To SmallPebble devs:
 Watch out for cases where NumPy and CuPy differ, 
 e.g. np.add.at is cupy.scatter_add.
 """
@@ -32,7 +46,6 @@ def use(array_library: ModuleType) -> None:
     sp.use(numpy)
     ```
     """
-
     global library
     library = array_library
 
@@ -41,19 +54,17 @@ def __getattr__(name: str):
     """Make this module act as a proxy, for NumPy/CuPy.
 
     Here's an example:
-    
     ```python
     import smallpebble.array_library as array_library
-    
+
     x = array_library.array([1, 2, 3]) ** 2  # <- a NumPy array
     ```
-
     In this example, a NumPy array is created,
     because `array_library.array` results in this function
     being called, which then calls `getattr(numpy, "array")`,
     which is NumPy's function for creating arrays.
-    (The above assumes that `library == numpy`, which is the 
+    (The above assumes that `library == numpy`, which is the
     default. The same thing would happen but with CuPy arrays,
-    if `library == cupy`.) 
+    if `library == cupy`.)
     """
     return getattr(library, name)