Simplify

Author: marcelm

Lib/_pyio.py

@@ -999,12 +999,9 @@ def tell(self):
     def peek(self, size=1):
         if self.closed:
             raise ValueError("peek on closed file")
-        # Due to slicing semantics, this works correctly
-        # even if the size is greater than the buffer length or
-        # the position is beyond the end of the buffer
         if size < 0:
-            size = len(self._buffer) - self._pos
-        return self._buffer[self._pos : self._pos + size]
+            return self._buffer[self._pos:]
+        return self._buffer[self._pos:self._pos + size]
 
     def truncate(self, pos=None):
         if self.closed: