Further improve docstring for read_nonblocking.

1 files changed, 10 insertions, 2 deletions

diff --git a/pexpect/fdpexpect.py b/pexpect/fdpexpect.py
index 785bc10..40817b9 100644
--- a/pexpect/fdpexpect.py
+++ b/pexpect/fdpexpect.py
@@ -115,10 +115,18 @@ class fdspawn(SpawnBase):
             self.write(s)
 
     def read_nonblocking(self, size=1, timeout=-1):
-        """The read_nonblocking method of SpawnBase assumes that a call to
+        """ Read from the file descriptor and return the result as a string.
+
+        The read_nonblocking method of SpawnBase assumes that a call to
         os.read will not block. This is not the case for POSIX file like
         objects like sockets and serial ports. So we use select to implement
-        the timeout on POSIX."""
+        the timeout on POSIX.
+
+        :param size:    Read at most size bytes
+        :param timeout: Wait timeout seconds for file descriptor to be ready
+                        to read. If -1, use self.timeout. If 0, poll.
+        :return:        String containing the bytes read
+        """
         if os.name == 'posix':
             if timeout == -1:
                 timeout = self.timeout