Skip to content

Diagram¶

Schema visualization

Diagram visualization for DataJoint schemas.

This module provides the Diagram class for visualizing schema structure as directed acyclic graphs showing tables and their foreign key relationships.

Diagram ¶

Bases: DiGraph

Schema diagram as a directed acyclic graph (DAG).

Visualizes tables and foreign key relationships derived from connection.dependencies.

Parameters:

Name Type Description Default
source Table, Schema, or module

A table object, table class, schema, or module with a schema.

 required
context dict

Namespace for resolving table class names. If None, uses caller's frame globals/locals.

 None

Examples:

>>> diag = dj.Diagram(schema.MyTable)
>>> diag.draw()

Operators:

  • diag1 + diag2 - union of diagrams
  • diag1 - diag2 - difference of diagrams
  • diag1 * diag2 - intersection of diagrams
  • diag + n - expand n levels of successors (children)
  • diag - n - expand n levels of predecessors (parents)
>>> dj.Diagram(schema.Table) + 1 - 1  # immediate ancestors and descendants
Notes

diagram + 1 - 1 may differ from diagram - 1 + 1. Only tables loaded in the connection are displayed.

Layout direction is controlled via dj.config.display.diagram_direction (default "TB"). Use dj.config.override() to change temporarily::

with dj.config.override(display_diagram_direction="LR"):
    dj.Diagram(schema).draw()

from_sequence classmethod ¶

from_sequence(sequence)

Create combined Diagram from a sequence of sources.

Parameters:

Name Type Description Default
sequence iterable

Sequence of table objects, classes, or schemas.

 required

Returns:

Type Description
Diagram

Union of diagrams: Diagram(arg1) + ... + Diagram(argn).

add_parts ¶

add_parts()

Add part tables of all masters already in the diagram.

Returns:

Type Description
Diagram

New diagram with part tables included.

collapse ¶

collapse()

Mark all nodes in this diagram as collapsed.

Collapsed nodes are shown as a single node per schema. When combined with other diagrams using +, expanded nodes win: if a node is expanded in either operand, it remains expanded in the result.

Returns:

Type Description
Diagram

A copy of this diagram with all nodes collapsed.

Examples:

>>> # Show schema1 expanded, schema2 collapsed into single nodes
>>> dj.Diagram(schema1) + dj.Diagram(schema2).collapse()

>>> # Collapse all three schemas together
>>> (dj.Diagram(schema1) + dj.Diagram(schema2) + dj.Diagram(schema3)).collapse()

>>> # Expand one table from collapsed schema
>>> dj.Diagram(schema).collapse() + dj.Diagram(SingleTable)

topo_sort ¶

topo_sort()

Return nodes in topological order.

Returns:

Type Description
list[str]

Node names in topological order.

make_dot ¶

make_dot()

Generate a pydot graph object.

Returns:

Type Description
Dot

The graph object ready for rendering.
Notes

Layout direction is controlled via dj.config.display.diagram_direction. Tables are grouped by schema, with the Python module name shown as the group label when available.

make_mermaid ¶

make_mermaid()

Generate Mermaid diagram syntax.

Produces a flowchart in Mermaid syntax that can be rendered in Markdown documentation, GitHub, or https://mermaid.live.

Returns:

Type Description
str

Mermaid flowchart syntax.
Notes

Layout direction is controlled via dj.config.display.diagram_direction. Tables are grouped by schema using Mermaid subgraphs, with the Python module name shown as the group label when available.

Examples:

>>> print(dj.Diagram(schema).make_mermaid())
flowchart TB
    subgraph my_pipeline
        Mouse[Mouse]:::manual
        Session[Session]:::manual
        Neuron([Neuron]):::computed
    end
    Mouse --> Session
    Session --> Neuron

save ¶

save(filename, format=None)

Save diagram to file.

Parameters:

Name Type Description Default
filename str

Output filename.

 required
format str

File format ('png', 'svg', or 'mermaid'). Inferred from extension if None.

 None

Raises:

Type Description
DataJointError

If format is unsupported.
Notes

Layout direction is controlled via dj.config.display.diagram_direction. Tables are grouped by schema, with the Python module name shown as the group label when available.