Manipulate, verify and de/serialize asset administration shells in Micropython.
This is a semantically patched version of the aas-core3.0-python SDK so that it can run in the Micropython environment.
We continuously patch the original Python SDK, so that the version between the two code bases correspond.
Micropython supports only a subset of the CPython standard library. This also constraints what we can implement in the SDK. Due to the limitations we had to exclude:
- XML de-serialization, as there is no mature XML parser in Micropython, and
- Verification, as the regular expression module in Micropython lacks counted repetitions and does not work on escaped characters.
The XML serialization, however, is included as the original library directly writes to a text stream, without dependence on an external library.
We follow the versioning of the original SDK that we patched.
We provide a [package.json](package.json), so you can directly install using mpremote from this repository:
mpremote mip install github:aas-core-works/aas-core3.0-micropython
... or using mip:
micropython -m mip install github:aas-core-works/aas-core3.0-micropython
We document here a couple of code snippets so that you can quickly get started working with the library.
Please refer to `the original documentation of aas-core3.0-python`_ for more context and detailed information.
import aas_core3.types as aas_types
# Create the first element
some_element = aas_types.Property(
id_short="some_property", value_type=aas_types.DataTypeDefXSD.INT, value="1984"
)
# Create the second element
another_element = aas_types.Blob(
id_short="some_blob",
content_type="application/octet-stream",
value=b"\xDE\xAD\xBE\xEF",
)
# You can directly access the element properties.
another_element.value = b"\xDE\xAD\xC0\xDE"
# Nest the elements in a submodel
submodel = aas_types.Submodel(
id="some-unique-global-identifier",
submodel_elements=[some_element, another_element],
)
# Now create the environment to wrap it all up
environment = aas_types.Environment(submodels=[submodel])
# You can access the properties from the children as well.
environment.submodels[0].submodel_elements[1].value = b"\xC0\x01\xCA\xFE"
# Now you can do something with the environment...
import aas_core3.types as aas_types
# Prepare the environment
environment = aas_types.Environment(
submodels=[
aas_types.Submodel(
id="some-unique-global-identifier",
submodel_elements=[
aas_types.Property(
id_short="some_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1984",
),
aas_types.Property(
id_short="another_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1985",
),
aas_types.Property(
id_short="yet_another_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1986",
),
],
)
]
)
for something in environment.descend():
if (
isinstance(something, aas_types.Property)
and "another" in something.id_short
):
print(something.id_short)
# Prints:
# another_property
# yet_another_property
import aas_core3.types as aas_types
class Visitor(aas_types.PassThroughVisitor):
def visit_property(self, that: aas_types.Property):
if "another" in that.id_short:
print(that.id_short)
# Prepare the environment
environment = aas_types.Environment(
submodels=[
aas_types.Submodel(
id="some-unique-global-identifier",
submodel_elements=[
aas_types.Property(
id_short="some_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1984",
),
aas_types.Property(
id_short="another_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1985",
),
aas_types.Property(
id_short="yet_another_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1986",
),
],
)
]
)
# Iterate
visitor = Visitor()
visitor.visit(environment)
# Prints
# another_property
# yet_another_property
import aas_core3.types as aas_types
import aas_core3.jsonization as aas_jsonization
# Prepare the environment
environment = aas_types.Environment(
submodels=[
aas_types.Submodel(
id="some-unique-global-identifier",
submodel_elements=[
aas_types.Property(
id_short="some_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1984",
)
],
)
]
)
# Serialize to a JSON-able mapping
jsonable = aas_jsonization.to_jsonable(environment)
# Print the mapping as text
print(json.dumps(jsonable))
# Prints (as a continuous string without newlines and indention)
# {
# "submodels": [
# {
# "id": "some-unique-global-identifier",
# "submodelElements": [
# {
# "idShort": "some_property",
# "valueType": "xs:int",
# "value": "1984",
# "modelType": "Property"
# }
# ],
# "modelType": "Submodel"
# }
# ]
# }
import aas_core3.types as aas_types
import aas_core3.jsonization as aas_jsonization
text = """\
{
"submodels": [
{
"id": "some-unique-global-identifier",
"submodelElements": [
{
"idShort": "someProperty",
"valueType": "xs:boolean",
"modelType": "Property"
}
],
"modelType": "Submodel"
}
]
}"""
jsonable = json.loads(text)
environment = aas_jsonization.environment_from_jsonable(jsonable)
for something in environment.descend():
print(type(something))
# Prints
# <class 'aas_core3.types.Submodel'>
# <class 'aas_core3.types.Property'>
import aas_core3.types as aas_types
import aas_core3.xmlization as aas_xmlization
# Prepare the environment
environment = aas_types.Environment(
submodels=[
aas_types.Submodel(
id="some-unique-global-identifier",
submodel_elements=[
aas_types.Property(
id_short="some_property",
value_type=aas_types.DataTypeDefXSD.INT,
value="1984",
)
],
)
]
)
# Serialize to an XML-encoded string
text = aas_xmlization.to_str(environment)
print(text)
# Prints (without the newlines and indention)
# <environment xmlns="https://admin-shell.io/aas/3/0">
# <submodels>
# <submodel>
# <id>some-unique-global-identifier</id>
# <submodelElements>
# <property>
# <idShort>some_property</idShort>
# <valueType>xs:int</valueType>
# <value>1984</value>
# </property>
# </submodelElements>
# </submodel>
# </submodels>
# </environment>
As we noted above, there is no mature XML library for Micropython so we could not adapt the original code.