Scheme Serialization (readwrite
)
Scheme save/load routines.
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orangecanvas.scheme.readwrite.
dumps
(obj, format='literal', prettyprint=False, pickle_fallback=False) Serialize obj using format (‘json’ or ‘literal’) and return its string representation and the used serialization format (‘literal’, ‘json’ or ‘pickle’).
If pickle_fallback is True and the serialization with format fails object’s pickle representation will be returned
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orangecanvas.scheme.readwrite.
indent
(element, level=0, indent='\t') Indent an instance of a
Element
. Based on (http://effbot.org/zone/element-lib.htm#prettyprint).
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orangecanvas.scheme.readwrite.
literal_dumps
(obj, prettyprint=False, indent=4) Write obj into a string as a python literal.
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orangecanvas.scheme.readwrite.
parse_scheme
(scheme, stream, error_handler=None, allow_pickle_data=False) Parse a saved scheme from stream and populate a scheme instance (
Scheme
). error_handler if given will be called with an exception when a ‘recoverable’ error occurs. By default the exception is simply raised.Parameters: - scheme (
Scheme
) – A scheme instance to populate with the contents of stream. - stream (file-like object) – A file like object opened for reading.
- error_hander (function, optional) – A function to call with an exception instance when a recoverable error occurs.
- allow_picked_data (bool, optional) – Specifically allow parsing of picked data streams.
- scheme (
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orangecanvas.scheme.readwrite.
parse_scheme_v_1_0
(etree, scheme, error_handler, widget_registry=None, allow_pickle_data=False) ElementTree Instance of an old .ows scheme format.
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orangecanvas.scheme.readwrite.
parse_scheme_v_2_0
(etree, scheme, error_handler, widget_registry=None, allow_pickle_data=False) Parse an ElementTree instance.
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orangecanvas.scheme.readwrite.
scheme_node_from_element
(node_el, registry) Create a SchemeNode from an Element instance.
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orangecanvas.scheme.readwrite.
scheme_to_etree
(scheme, data_format='literal', pickle_fallback=False) Return an xml.etree.ElementTree representation of the scheme.
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orangecanvas.scheme.readwrite.
scheme_to_ows_stream
(scheme, stream, pretty=False, pickle_fallback=False) Write scheme to a a stream in Orange Scheme .ows (v 2.0) format.
Parameters: - scheme (
Scheme
) – AScheme
instance to serialize. - stream (file-like object) – A file-like object opened for writing.
- pretty (bool, optional) – If True the output xml will be pretty printed (indented).
- pickle_fallback (bool, optional) – If True allow scheme node properties to be saves using pickle protocol if properties cannot be saved using the default notation.
- scheme (
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orangecanvas.scheme.readwrite.
sniff_version
(stream) Parse a scheme stream and return the scheme’s serialization version string.
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orangecanvas.scheme.readwrite.
string_eval
(source) Evaluate a python string literal source. Raise ValueError if source is not a string literal.
>>> string_eval("'a string'") a string
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orangecanvas.scheme.readwrite.
terminal_eval
(source) Evaluate a python ‘constant’ (string, number, None, True, False) source. Raise ValueError is not a terminal literal.
>>> terminal_eval("True") True
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orangecanvas.scheme.readwrite.
tuple_eval
(source) Evaluate a python tuple literal source where the elements are constrained to be int, float or string. Raise ValueError if not a tuple literal.
>>> tuple_eval("(1, 2, "3")") (1, 2, '3')