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PythonObjectProperty

This is a Python binding to the C++ class Mantid::PythonInterface::PythonObjectProperty. It is meant to hold a generic python object as a property for use in algorithms defined from python.

bases: mantid.kernel.PropertyWithValue

class mantid.kernel.PythonObjectProperty

EMPTY_DBL = 8.988465674311579e+307

EMPTY_INT = 2147483647

EMPTY_LONG = 9223372036854775807

property allowedValues

A list of allowed values

property direction

Input, Output, InOut or Unknown. See the Direction class

property documentation

The property’s doc string

dtype((PythonObjectPropertyWithValue)self) → str

getAutoTrim((Property)arg1) → bool :

Gets the setting of automatic trimming of whitespaces.

property getDefault

Get the default value as a string

property getGroup

Return the ‘group’ of the property, that is, the header in the algorithm’s list of properties.

property isDefault

Is the property set at the default value

property isValid

An empty string if the property is valid, otherwise it contains an error message.

property name

The name of the property

setAutoTrim((Property)arg1, (bool)setting) → None :

Setting automatic trimming of whitespaces.

setDisableReplaceWSButton((Property)arg1, (bool)disable) → None :

Disable the creation of the Replace Workspace button.

setDocumentation((Property)arg1, (str)doc) → None :

Setting documentation for property

setValue((PythonObjectProperty)arg1, (object)arg2) → str

property settings

Return the object managing this property’s settings

property type

Returns a string identifier for the type

property units

The units attached to this property

property unitsAsBytes

The units attached to this property as a encoded bytes object. It is assumed the caller knows the correct endcoding used.

property value

None( (mantid.kernel._kernel.PythonObjectPropertyWithValue)arg1) -> object

valueAsPrettyStr((Property)arg1[, (int)maxLength=0[, (bool)collapseLists=True]]) → str :

The value of the property as a formatted string. If maxLength is defined then the output may not contain the full contents of the property. The maxLength and collapseLists arguments do not work for all property types

property valueAsStr

The value of the property as a string. For some property types, e.g. Workspaces, it is useful to be able to refer to the string value directly

Example Usage

The following example shows how to use this property type, both with and without a PythonObjectTypeValidator.

from mantid.kernel import PythonObjectProperty, PythonObjectTypeValidator
from mantid.api import PythonAlgorithm

class FakeClass:
    pass

class FakeAlgorithm(PythonAlgorithm):
    def PyInit(self):
        self.declareProperty(PythonObjectProperty("UnvalidatedPyObject"))
        self.declareProperty(PythonObjectProperty("ValidatedPyObject", None, PythonObjectTypeValidator(FakeClass)))

    def PyExec(self):
        pass

value1 = {"key1": "value one", "key2": ["one", "two", "three"]}
value2 = FakeClass()

# run the algorithm
fake = FakeAlgorithm()
fake.initialize()
fake.setProperty("UnvalidatedPyObject", value1)
fake.setProperty("ValidatedPyObject", value2)
fake.execute()

Notes

When string values are required, this will first attempt to write them using json.dumps. If that does not work then serialization will recursively build a json-like object, including replacing custom classes with __dict__ property. Note that for very complicated objects, this can result in enormous string outputs. It is recommended to stick to simpler python types, or classes made from simple python types. This will not work on objects that use python tuples for dictionary keys. If the recursive serialization fails, the string value will be set to "<unrepresentable object>".