Fix for chained constructors

Author: lshaw8317

src/blosc2/lazyexpr.py

@@ -2561,11 +2561,20 @@ def shape(self):
             return None
 
         # Operands shape can change, so we always need to recompute this
-        _shape, chunks, blocks, fast_path = validate_inputs(self.operands, getattr(self, "_out", None))
-        if fast_path:
-            # fast_path ensure that all the operands have the same partitions
-            self._chunks = chunks
-            self._blocks = blocks
+        try:
+            _shape, chunks, blocks, fast_path = validate_inputs(self.operands, getattr(self, "_out", None))
+            if fast_path:
+                # fast_path ensure that all the operands have the same partitions
+                self._chunks = chunks
+                self._blocks = blocks
+        except ValueError as e:
+            if any(constructor in self.expression for constructor in constructors):
+                # might have an expression with pure constructors
+                opshapes = {k: v if not hasattr(v, "shape") else v.shape for k, v in self.operands.items()}
+                _shape = infer_shape(self.expression, opshapes)  # infer shape, includes constructors
+            else:
+                raise e
+
         self._shape_ = _shape
         self._expression_ = self.expression
         return _shape