Param¶

class igwn_ligolw.ligolw.Param(attrs=None)¶

Bases: Element

Param element. The value is stored in the pcdata attribute as the native Python type rather than as a string.

Attributes Summary

`DataUnit`	The "DataUnit" attribute.
`Name`	The "Name" attribute.
`Scale`	The "Scale" attribute.
`Start`	The "Start" attribute.
`Type`	The "Type" attribute.
`Unit`	The "Unit" attribute.
`tagName`
`validchildren`
`value`	Synonym of .pcdata.

Methods Summary

`build`(name, Type, value[, start, scale, ...])	Construct a LIGO Light Weight XML Param document subtree.
`endElement`()	Method invoked by document parser when it encounters the end-of-element event.
`from_pyvalue`(name, value, **kwargs)	Convenience wrapper for .build() that constructs a Param element from an instance of a Python builtin type.
`getParamsByName`(elem, name)	Return a list of params with name name under elem.
`get_param`(xmldoc[, name])	Scan xmldoc for a Param named name.
`write`([fileobj, indent])	Recursively write an element and it's children to a file.

Attributes Documentation

DataUnit¶: The “DataUnit” attribute.

Name¶: The “Name” attribute.

Scale¶: The “Scale” attribute.

Start¶: The “Start” attribute.

Type¶: The “Type” attribute. Default is “lstring” if not set.

Unit¶: The “Unit” attribute.

tagName = 'Param'¶

validchildren = frozenset({'Comment'})¶

value¶: Synonym of .pcdata. Makes calling code easier to understand. In the parent class .pcdata is text only. Here it has been translated into a native Python type, but it’s not obvious in calling code that that is what has happened so it can be unclear when reading calling codes if one should be expecting a string or a native value. Using this synonym can clarify the meaning.

Methods Documentation

classmethod build(name, Type, value, start=None, scale=None, unit=None, dataunit=None, comment=None)¶: Construct a LIGO Light Weight XML Param document subtree. FIXME: document keyword arguments.

endElement()¶: Method invoked by document parser when it encounters the end-of-element event.

classmethod from_pyvalue(name, value, **kwargs)¶

Convenience wrapper for .build() that constructs a Param element from an instance of a Python builtin type. See .build() for a description of the valid keyword arguments.

Examples:

>>> import sys
>>> # float
>>> Param.from_pyvalue("example", 3.0).write(sys.stdout)
<Param Name="example:param" Type="real_8">3</Param>
>>> # string
>>> Param.from_pyvalue("example", "test").write(sys.stdout)
<Param Name="example:param" Type="lstring">test</Param>
>>> # short string (non-empty data = not NULL)
>>> Param.from_pyvalue("example", "").write(sys.stdout)
<Param Name="example:param" Type="lstring"> </Param>
>>> # None (empty data = NULL)
>>> Param.from_pyvalue("example", None).write(sys.stdout)
<Param Name="example:param" Type="None"></Param>

Note that any type of Param may be NULL-valued. These examples demonstrate the use of the automatic encoding helper function, which translates None into a None-typed Param because it doesn’t know what else it might be, but, for example, a float-typed Param may also be set to None.

classmethod getParamsByName(elem, name)¶

Return a list of params with name name under elem.