8.2.3.1. Base

class Base

Base class for dispatcher objects.

Methods

get_node	Returns a sub node of a dispatcher.
plot	Plots the Dispatcher with a graph in the DOT language with Graphviz.
search_node_description
web	Creates a dispatcher Flask app.

__init__()

Initialize self. See help(type(self)) for accurate signature.

web(depth=-1, node_data=none, node_function=none, directory=None, sites=None, run=True)

Creates a dispatcher Flask app.

Parameters:

• depth (int, optional) – Depth of sub-dispatch plots. If negative all levels are plotted.
• node_data (tuple[str], optional) – Data node attributes to view.
• node_function (tuple[str], optional) – Function node attributes to view.
• directory (str, optional) – Where is the generated Flask app root located?
• sites (set[Site], optional) – A set of Site to maintain alive the backend server.
• run (bool, optional) – Run the backend server?

Returns:

A WebMap.

Return type:

WebMap

Example:

From a dispatcher like this:

>>> from schedula import Dispatcher
>>> dsp = Dispatcher(name='Dispatcher')
>>> def fun(a):
...     return a + 1, a - 1
>>> dsp.add_function('fun', fun, ['a'], ['b', 'c'])
'fun'

You can create a web server with the following steps:

>>> webmap = dsp.web()
>>> print("Starting...\n"); site = webmap.site().run(); site
Starting...
Site(WebMap([(Dispatcher, WebMap())]), host='localhost', ...)
>>> import requests
>>> url = '%s/%s/%s' % (site.url, dsp.name, fun.__name__)
>>> requests.post(url, json={'args': (0,)}).json()['return']
[1, -1]
>>> site.shutdown()  # Remember to shutdown the server.
True

Note

When Site is garbage collected the server is shutdown automatically.

plot(workflow=None, view=True, depth=-1, name=none, comment=none, format=none, engine=none, encoding=none, graph_attr=none, node_attr=none, edge_attr=none, body=none, node_styles=none, node_data=none, node_function=none, edge_data=none, max_lines=none, max_width=none, directory=None, sites=None, index=False)

Plots the Dispatcher with a graph in the DOT language with Graphviz.

Parameters:

• workflow (bool, optional) – If True the latest solution will be plotted, otherwise the dmap.
• view (bool, optional) – Open the rendered directed graph in the DOT language with the sys default opener.
• edge_data (tuple[str], optional) – Edge attributes to view.
• node_data (tuple[str], optional) – Data node attributes to view.
• node_function (tuple[str], optional) – Function node attributes to view.
• node_styles (dict[str|Token, dict[str, str]]) – Default node styles according to graphviz node attributes.
• depth (int, optional) – Depth of sub-dispatch plots. If negative all levels are plotted.
• name (str) – Graph name used in the source code.
• comment (str) – Comment added to the first line of the source.
• directory (str, optional) – (Sub)directory for source saving and rendering.
• format (str, optional) – Rendering output format (‘pdf’, ‘png’, …).
• engine (str, optional) – Layout command used (‘dot’, ‘neato’, …).
• encoding (str, optional) – Encoding for saving the source.
• graph_attr (dict, optional) – Dict of (attribute, value) pairs for the graph.
• node_attr (dict, optional) – Dict of (attribute, value) pairs set for all nodes.
• edge_attr (dict, optional) – Dict of (attribute, value) pairs set for all edges.
• body (dict, optional) – Dict of (attribute, value) pairs to add to the graph body.
• directory – Where is the generated Flask app root located?
• sites (set[Site], optional) – A set of Site to maintain alive the backend server.
• index (bool, optional) – Add the site index as first page?
• max_lines (int, optional) – Maximum number of lines for rendering node attributes.
• max_width (int, optional) – Maximum number of characters in a line to render node attributes.
• view – Open the main page of the site?

Returns:

A SiteMap.

Return type:

schedula.utils.drw.SiteMap

Example:

>>> from schedula import Dispatcher
>>> dsp = Dispatcher(name='Dispatcher')
>>> def fun(a):
...     return a + 1, a - 1
>>> dsp.add_function('fun', fun, ['a'], ['b', 'c'])
'fun'
>>> dsp.plot(view=False, graph_attr={'ratio': '1'})
SiteMap([(Dispatcher, SiteMap())])

get_node(*node_ids, node_attr=none)

Returns a sub node of a dispatcher.

Parameters:

• node_ids (str) – A sequence of node ids or a single node id. The id order identifies a dispatcher sub-level.
• node_attr (str, None, optional) –

  Output node attr.

  If the searched node does not have this attribute, all its attributes are returned.

  When ‘auto’, returns the “default” attributes of the searched node, which are:

  • for data node: its output, and if not exists, all its attributes.
  • for function and sub-dispatcher nodes: the ‘function’ attribute.

  When ‘description’, returns the “description” of the searched node, searching also in function or sub-dispatcher input/output description.

  When ‘output’, returns the data node output.

  When ‘default_value’, returns the data node default value.

  When ‘value_type’, returns the data node value’s type.

  When None, returns the node attributes.

Returns:

Node attributes and its real path.

Return type:

(T, (str, ..))

Example:

Get the sub node output:

>>> dsp.get_node('Sub-dispatcher', 'c')
(4, ('Sub-dispatcher', 'c'))
>>> dsp.get_node('Sub-dispatcher', 'c', node_attr='type')
('data', ('Sub-dispatcher', 'c'))

>>> sub_dsp, sub_dsp_id = dsp.get_node('Sub-dispatcher')