Avoid creating useless squeezes and expand_dims

pytensor/tensor/extra_ops.py

@@ -603,6 +603,10 @@ def squeeze(x, axis=None):
     except np.AxisError:
         raise np.AxisError(axis, ndim=_x.ndim)
 
+    if not axis:
+        # Nothing to do
+        return _x
+
     return _x.dimshuffle([i for i in range(_x.ndim) if i not in axis])
 
 

pytensor/tensor/shape.py

@@ -868,7 +868,8 @@ def shape_padleft(t, n_ones=1):
 
     """
     _t = at.as_tensor_variable(t)
-
+    if n_ones == 0:
+        return _t
     pattern = ["x"] * n_ones + list(range(_t.type.ndim))
     return _t.dimshuffle(pattern)
 
@@ -884,7 +885,8 @@ def shape_padright(t, n_ones=1):
 
     """
     _t = at.as_tensor_variable(t)
-
+    if n_ones == 0:
+        return _t
     pattern = list(range(_t.type.ndim)) + ["x"] * n_ones
     return _t.dimshuffle(pattern)