Factor out the parsing of a valid cell run in the generic ipython implementation

run_cell() becomes more complicated when we add ipython version 3
support which upsets pylint because there are "too many
branches (15/12)".  Factor out part of the function to make pylint
happy.

wlauto/utils/ipython.py

@@ -48,28 +48,13 @@ elif IPython:
     import_error_str = 'Unsupported IPython version {}'.format(IPython_ver_str)
 
 
-def run_cell(kernel_client, cell):
-    """Run a cell of a notebook in an ipython kernel and return its output"""
-    kernel_client.execute(cell.input)
-
-    input_acknowledged = False
-    outs = []
-    while True:
-        msg = kernel_client.get_iopub_msg()
-
+def parse_valid_output(msg):
+    """Parse a valid result from an execution of a cell in an ipython kernel"""
     msg_type = msg["msg_type"]
     content = msg["content"]
     out = NotebookNode(output_type=msg_type)
 
-        if msg_type == "status":
-            if content["execution_state"] == "idle" and input_acknowledged:
-                break
-            else:
-                continue
-        elif msg_type == "pyin":
-            input_acknowledged = True
-            continue
-        elif msg_type == "stream":
+    if msg_type == "stream":
         out.stream = content["name"]
         out.text = content["data"]
     elif msg_type in ("display_data", "pyout"):
@@ -86,6 +71,25 @@ def run_cell(kernel_client, cell):
     else:
         raise ValueError("Unknown msg_type {}".format(msg_type))
 
+    return out
+
+
+def run_cell(kernel_client, cell):
+    """Run a cell of a notebook in an ipython kernel and return its output"""
+    kernel_client.execute(cell.input)
+
+    input_acknowledged = False
+    outs = []
+    while True:
+        msg = kernel_client.get_iopub_msg()
+
+        if msg["msg_type"] == "status":
+            if msg["content"]["execution_state"] == "idle" and input_acknowledged:
+                break
+        elif msg["msg_type"] == "pyin":
+            input_acknowledged = True
+        else:
+            out = parse_valid_output(msg)
             outs.append(out)
 
     return outs