python: common base handle for SPI + USB (#1231)

* base handle

* usb handle

* rm

* more types

python/base.py

@@ -0,0 +1,25 @@
+from abc import ABC, abstractmethod
+from typing import List
+
+
+# This mimics the handle given by libusb1 for easy interoperability
+class BaseHandle(ABC):
+  @abstractmethod
+  def close(self) -> None:
+    ...
+
+  @abstractmethod
+  def controlWrite(self, request_type: int, request: int, value: int, index: int, data, timeout: int = 0) -> int:
+    ...
+
+  @abstractmethod
+  def controlRead(self, request_type: int, request: int, value: int, index: int, length: int, timeout: int = 0) -> bytes:
+    ...
+
+  @abstractmethod
+  def bulkWrite(self, endpoint: int, data: List[int], timeout: int = 0) -> int:
+    ...
+
+  @abstractmethod
+  def bulkRead(self, endpoint: int, length: int, timeout: int = 0) -> bytes:
+    ...