memory-graph 0.1.2

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 )

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. Use block=False to turn off blocking.

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

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, 30]

class My_Class:
    my_class_var = 1000 # class variable: shared by different objects
    
    def __init__(self):
        self.var1 = "foo"
        self.var2 = "bar"

obj1 = My_Class()
obj2 = My_Class()

data=[my_list, my_list, obj1, obj2]

my_list.append(data) # recursive reference

memory_graph.show( data )

Often it is useful to show all local variables using:

memory_graph.show( memory_graph.filter(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

See for color names: graphviz colors

To configure more about the visualization use:

digraph = memory_graph.create_graph( memory_graph.filter(locals()) )

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

Config node 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 copy 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 references (to dict) in objects of classes
• memory_graph.rewrite_to_node.class_variables_label : str
  • the label used to reference the class varibles (mappingproxy)

Config node creation, rewrite

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

• 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)

Config example

With configuration:

memory_graph.graphviz_nodes.layout_vertical = True                        # draw list/tuple/set/... vertically
memory_graph.graphviz_nodes.type_category_to_color_map['list'] = 'yellow' # change color of 'list' types
memory_graph.rewrite_to_node.reduce_reference_types.remove(int)           # draw references to 'int' types

the last example looks like:

Author

Bas Terwijn

Inspiration

Inspired by PythonTutor.