Add space for pep8 in documentation

doc/library/tensor/basic.txt

-
 .. currentmodule:: tensor
 
 .. _libdoc_basic_tensor:
@@ -548,13 +547,13 @@ dimensions, see :meth:`_tensor_py_operators.dimshuffle`.
 .. function:: unbroadcast(x, *axes)
 
     Make `x` impossible to broadcast in the specified axes `axes`. For
-    example, `unbroadcast(x,0)` will make the first dimension of `x`
+    example, `unbroadcast(x, 0)` will make the first dimension of `x`
     unbroadcastable.
 
 .. function:: addbroadcast(x, *axes)
 
     Make `x` broadcastable in the specified axes `axes`. For
-    example, `addbroadcast(x,0)` will make the first dimension of `x`
+    example, `addbroadcast(x, 0)` will make the first dimension of `x`
     broadcastable. When performing the function, if the length of `x`
     along that dimension is not 1, a ``ValueError`` will be raised.
 
@@ -573,7 +572,7 @@ dimensions, see :meth:`_tensor_py_operators.dimshuffle`.
         dimensions, but with all remaining dimensions of `x` collapsed into
         the last dimension.
 
-    For example, if we flatten a tensor of shape (2,3,4,5) with flatten(x,
+    For example, if we flatten a tensor of shape (2, 3, 4, 5) with flatten(x,
     outdim=2), then we'll have the same (2-1=1) leading dimensions (2,), and the
     remaining dimensions are collapsed.  So the output in this example would
     have shape (2, 60).