return child as nested list from memory_usage

Author: bbengfort

README.rst

@@ -191,9 +191,9 @@ This will create a plot using matplotlib similar to this:
     :height: 350px
 
 You can combine both the ``include_children`` and ``multiprocess`` flags to show
-the total memory of the program as well as each child individually.
-
-.. warning:: Currently the child tracking only works if a ``stream`` is provided to the ``profile`` (e.g. from the command line or in the decorator). If you are using the API to retrieve values then the flag will not do anything.
+the total memory of the program as well as each child individually. If using
+the API directly, note that the return from ``memory_usage`` will include the
+child memory along with an index identifying the specific child.
 
 Setting debugger breakpoints
 =============================

memory_profiler.py

@@ -353,14 +353,19 @@ def memory_usage(proc=-1, interval=.1, timeout=None, timestamps=False,
                 if stream is not None:
                     stream.write("MEM {0:.6f} {1:.4f}\n".format(*mem_usage))
 
-                    # Only write children to the stream file, warn if appending to the return.
+                    # Write children to the stream file
                     if multiprocess:
                         for idx, chldmem in enumerate(_get_child_memory(proc.pid)):
                             stream.write("CHLD {0} {1:.6f} {2:.4f}\n".format(idx, chldmem, time.time()))
                 else:
-                    ret.append(mem_usage)
+                    # Create a nested list with the child memory
                     if multiprocess:
-                        warnings.warn("use include_children not multiprocess without a stream")
+                        mem_usage = [mem_usage]
+                        for chldmem in _get_child_memory(proc.pid):
+                            mem_usage.append(chldmem)
+
+                    # Append the memory usage to the return value
+                    ret.append(mem_usage)
             else:
                 ret = max(ret,
                           _get_memory(
@@ -392,15 +397,19 @@ def memory_usage(proc=-1, interval=.1, timeout=None, timestamps=False,
                 if stream is not None:
                     stream.write("MEM {0:.6f} {1:.4f}\n".format(*mem_usage))
 
-                    # Only write children to the stream file, warn if appending to the return.
+                    # Write children to the stream file
                     if multiprocess:
                         for idx, chldmem in enumerate(_get_child_memory(proc.pid)):
                             stream.write("CHLD {0} {1:.6f} {2:.4f}\n".format(idx, chldmem, time.time()))
                 else:
-                    ret.append(mem_usage)
-
+                    # Create a nested list with the child memory
                     if multiprocess:
-                        warnings.warn("use include_children not multiprocess without a stream")
+                        mem_usage = [mem_usage]
+                        for chldmem in _get_child_memory(proc.pid):
+                            mem_usage.append(chldmem)
+
+                    # Append the memory usage to the return value
+                    ret.append(mem_usage)
             else:
                 ret = max([ret,
                            _get_memory(proc, backend, include_children=include_children)