diff --git a/python/adios2/adios.py b/python/adios2/adios.py
index 2e7ad7aab2..94b07f61f2 100644
--- a/python/adios2/adios.py
+++ b/python/adios2/adios.py
@@ -5,8 +5,12 @@
 
 
 class ADIOS:
-    def __init__(self):
-        self._impl = bindings.ADIOS()
+    def __init__(self, comm=None):
+        if comm:
+            self._impl = bindings.ADIOS(comm=comm)
+        else:
+            self._impl = bindings.ADIOS()
+
         self._operators = {}
         self._ios = {}
 
diff --git a/python/adios2/io.py b/python/adios2/io.py
index 7bf3cf345a..f777203beb 100644
--- a/python/adios2/io.py
+++ b/python/adios2/io.py
@@ -51,7 +51,7 @@ def DefineVariable(
         shape=[],
         start=[],
         count=[],
-        isConstantDims=bindings.ConstantDims,
+        isConstantDims=False,
     ):
         if isinstance(content, np.ndarray):
             #if shape is None:
diff --git a/python/adios2/stream.py b/python/adios2/stream.py
index 66a3bbe9d1..53f83b57a2 100644
--- a/python/adios2/stream.py
+++ b/python/adios2/stream.py
@@ -24,9 +24,9 @@ def typeAdiosToNumPy(name):
 
 
 class Stream:
-    def __init__(self, path, mode="r", engine_type="BPStream", config_file=None):
+    def __init__(self, path, mode="r", comm=None, engine_type="BPStream", config_file=None):
         self._io_name = f"stream:{path}:engine_type:{engine_type}"
-        self._adios = ADIOS()
+        self._adios = ADIOS(comm=comm)
         self._io = self._adios.DeclareIO(self._io_name)
         self._mode = mode
 
@@ -42,7 +42,7 @@ def __init__(self, path, mode="r", engine_type="BPStream", config_file=None):
         self.max_steps = 0
 
     def __repr__(self):
-        return f"<adios.file named {self._name} and mode {self._mode}>"
+        return f"<adios.file named {self._io_name} and mode {self._mode}>"
 
     def __enter__(self):
         return self
@@ -322,3 +322,6 @@ def steps(self, num_steps=0):
 
         self.index = 0
         return self
+
+    def num_steps(self, num_steps=0):
+        return self._engine.Steps()
diff --git a/testing/adios2/python/TestBPWriteTypesHighLevelAPI.py b/testing/adios2/python/TestBPWriteTypesHighLevelAPI.py
index 7ee9788f83..2a083eb66c 100644
--- a/testing/adios2/python/TestBPWriteTypesHighLevelAPI.py
+++ b/testing/adios2/python/TestBPWriteTypesHighLevelAPI.py
@@ -29,9 +29,10 @@
 # Writer
 with Stream("types_np.bp", "w", comm) as s:
 
-    for i in range(0, 5):
-        data.update(rank, i, size)
-        if rank == 0 and i == 0:
+    for step in s.steps(5):
+        data.update(rank, step.current_step(), size)
+        #s.write("rank", np.array(rank), shape=[adios2.LocalValueDim])
+        if rank == 0 and step.current_step() == 0:
             s.write("tag", "Testing ADIOS2 high-level API")
             s.write("gvarI8", np.array(data.I8[0]))
             s.write("gvarI16", np.array(data.I16[0]))
@@ -70,8 +71,8 @@
             s.write_attribute("attrR32Array", data.R32)
             s.write_attribute("attrR64Array", data.R64)
 
-        s.write("rank", np.array(rank), [adios2.LocalValueDim])
-        s.write("steps", "Step:" + str(i))
+        #breakpoint()
+        s.write("steps", "Step:" + str(step.current_step() ))
         s.write("varI8", data.I8, shape, start, count)
         s.write("varI16", data.I16, shape, start, count)
         s.write("varI32", data.I32, shape, start, count)
@@ -83,7 +84,7 @@
         s.write("varR32", data.R32, shape, start, count)
         s.write("varR64", data.R64, shape, start, count)
 
-        if rank == 0 and i == 0:
+        if rank == 0 and step.current_step() == 0:
             s.write_attribute("varattrStrArray", [
                 "varattr1", "varattr2", "varattr3"], "steps")
             s.write_attribute("varattrI8Array", data.I8, "varI8")
@@ -98,8 +99,6 @@
             s.write_attribute("varattrR64Array", data.R64, "varR64")
             s.write_attribute("varattrR64Value", data.R64, "varR64")
 
-        s.end_step()
-
 comm.Barrier()
 
 # Reader
@@ -108,9 +107,9 @@
 with Stream("types_np.bp", "r", comm) as fr:
 
     # file only
-    assert (fr.steps() == 5)
+    assert (fr.num_steps() == 5)
 
-    for fr_step in fr:
+    for fr_step in fr.steps():
 
         step = fr_step.current_step()
         data.update(rank, step, size)
@@ -124,7 +123,7 @@
 #             print("\n")
 
         if step == 0:
-            inTag = fr_step.read_string("tag")
+            inTag = fr_step.read("tag")
             inI8 = fr_step.read("gvarI8")
             inI16 = fr_step.read("gvarI16")
             inI32 = fr_step.read("gvarI32")
@@ -136,7 +135,7 @@
             inR32 = fr_step.read("gvarR32")
             inR64 = fr_step.read("gvarR64")
 
-            if inTag[0] != "Testing ADIOS2 high-level API":
+            if inTag != "Testing ADIOS2 high-level API":
                 print("InTag: " + str(inTag))
                 raise ValueError('tag variable read failed')
 
@@ -171,7 +170,8 @@
                 raise ValueError('gvarR64 read failed')
 
             # attributes
-            inTag = fr_step.read_attribute_string("attrStr")
+            breakpoint()
+            inTag = fr_step.read_attribute("attrStr")
             inI8 = fr_step.read_attribute("attrI8")
             inI16 = fr_step.read_attribute("attrI16")
             inI32 = fr_step.read_attribute("attrI32")
@@ -183,7 +183,7 @@
             inR32 = fr_step.read_attribute("attrR32")
             inR64 = fr_step.read_attribute("attrR64")
 
-            if inTag[0] != "Testing single string attribute":
+            if inTag != "Testing single string attribute":
                 raise ValueError('attr string read failed')
 
             if inI8[0] != data.I8[0]: