Fix type annotations and docs.

mem_edit/abstract.py

@@ -206,7 +206,7 @@ class Process(metaclass=ABCMeta):
     def get_pid_by_name(target_name: str) -> int or None:
         """
         Attempt to return the process id (pid) of a process which was run with an executable
-          file with the provided name.
+          file with the provided name. If no process is found, return None.
 
         This is a convenience method for quickly finding a process which is already known
           to be unique and has a well-defined executable name.
@@ -214,6 +214,7 @@ class Process(metaclass=ABCMeta):
         Don't rely on this method if you can possibly avoid it, since it makes no
           attempt to confirm that it found a unique process and breaks trivially (e.g. if the
           executable file is renamed).
+        :return: Process id (pid) of a process with the provided name, or None.
         """
         pass 
     

mem_edit/linux.py

@@ -91,7 +91,7 @@ class Process(AbstractProcess):
         return pids
 
     @staticmethod
-    def get_pid_by_name(target_name: str) -> int:
+    def get_pid_by_name(target_name: str) -> int or None:
         for pid in Process.list_available_pids():
             try:
                 logger.info('Checking name for pid {}'.format(pid))
@@ -123,5 +123,3 @@ class Process(AbstractProcess):
                 start, stop = (int(bound, 16) for bound in bounds.split('-'))
                 regions.append((start, stop))
         return regions
-
-

mem_edit/windows.py

@@ -193,7 +193,7 @@ class Process(AbstractProcess):
         return pids[:num_returned]
 
     @staticmethod
-    def get_pid_by_name(target_name: str) -> int:
+    def get_pid_by_name(target_name: str) -> int or None:
         for pid in Process.list_available_pids():
             try:
                 logger.info('Checking name for pid {}'.format(pid))