memory-graph 0.1.13

Draw a graph of your data to see the structure of its references.

Graph your Memory

Want to draw a graph of your data in Python to better understand its structure or the Python memory model in general?

Just call memory_graph.show(your_data), an example:

import memory_graph

data = [ (1, 2), [3, 4], {5:'five', 6:'six'} ]
memory_graph.show( data, block=True )

This shows the graph with the starting point of your 'data' drawn using thick lines, the program blocks until the ENTER key is pressed.

If show() doesn't work well on your system (the PDF viewer integration is platform specific) use render() to output the graph in the format of your choosing and open it yourself.

memory_graph.render( data, "my_graph.png", block=True )

Graph all Local Variables

Often it is useful to graph all the local variables using:

memory_graph.show( locals(), block=True )

Also useful to set as 'watch' in a debugger tool:

memory_graph.render( locals(), "my_debug_graph.pdf" )

Larger Example

This larger example shows objects that share a class (static) variable and also shows we can handle recursive references just fine.

import memory_graph

my_list = [10, 20, 10]

class My_Class:
    my_class_var = 20 # class variable: shared by different objects
    
    def __init__(self):
        self.var1 = "foo"
        self.var2 = "bar"
        self.var3 = 20

obj1 = My_Class()
obj2 = My_Class()

data=[my_list, my_list, obj1, obj2]

my_list.append(data) # recursive reference

memory_graph.show( locals() )

Install

Install using pip:

pip install memory-graph

Config

Different aspects of memory_graph can be configured.

Config Visualization, graphviz_nodes

Configure how the nodes of the graph are visualized with:

• memory_graph.graphviz_nodes.layout_vertical : bool
  • determines if list/tuple/... are drawn vertically
• memory_graph.graphviz_nodes.type_category_to_color_map : dict
  • a mapping from type to color
• memory_graph.graphviz_nodes.uncategorized_color : string
  • color used for uncategorized types
• memory_graph.graphviz_nodes.padding : int
  • amount of padding for node cells
• memory_graph.graphviz_nodes.spacing : int
  • amount of spacing for node cells
• memory_graph.graphviz_nodes.graph_attr : dict
  • allows to set various graphviz graph attributes
• memory_graph.graphviz_nodes.node_attr : dict
  • allows to set various graphviz node attributes
• memory_graph.graphviz_nodes.edge_attr : dict
  • allows to set various graphviz edges attributes

See for color names: graphviz colors

To configure more about the visualization use:

digraph = memory_graph.create_graph( locals() )

and see the graphviz api to render it in many different ways.

Config Graph Structure, rewrite_to_node

Configure the structure of the nodes in the graph with:

• memory_graph.rewrite_to_node.reduce_reference_types : set
  • the types we add to a node instead of drawing a reference to it
• memory_graph.rewrite_to_node.reduce_references_for_classes : bool
  • determines if we reduce the reference (to dictionary) for classes

Config Node Creation, rewrite

Configure what nodes are created based on reading the given data structure:

• memory_graph.rewrite.ignore_types : set
  • all types that we ignore, these will not be in the graph
• memory_graph.rewrite.singular_types : set
  • all types rewritten to node as singular values (bool, int, float, ...)
• memory_graph.rewrite.linear_types : set
  • all types rewritten to node as linear values (tuple, list, set, ...)
• memory_graph.rewrite.dict_types : set
  • all types rewritten to node as dictionary values (dict, mappingproxy)
• memory_graph.rewrite.dict_ignore_dunder_keys : bool
  • determines if we ignore dunder keys ('__example') in dict_types
• memory_graph.rewrite.rewrite_generators : bool
  • determines if we read and rewrite a generator to node
• memory_graph.rewrite.rewrite_any_iterable : bool
  • determines if we rewrite any iterable to node

Config example

With configuration:

memory_graph.graphviz_nodes.layout_vertical = False                       # draw lists,tuples,sets,... horizontally
memory_graph.graphviz_nodes.type_category_to_color_map['list'] = 'yellow' # change color of 'list' type
memory_graph.graphviz_nodes.spacing=15                                    # more spacing in each node
memory_graph.graphviz_nodes.graph_attr['ranksep']='1.2'                   # more vertical separation
memory_graph.graphviz_nodes.graph_attr['nodesep']='1.2'                   # more horizontal separation
memory_graph.rewrite_to_node.reduce_reference_types.remove(int)           # draw references to 'int' type

the last example looks like:

Troubleshooting

When edges overlap it can be hard to distinguish them. Using an interactive graphviz viewer, such as xdot, on a '*.gv' output file will help.

Author

Bas Terwijn

Inspiration

Inspired by PythonTutor.