ngsildclient.utils.urn#

This module contains helper functions to URI/URN in the NGSI-LD namespace.

References

2: ETSI, 2021. “NGSI-LD namespace” in Context Information Management (CIM); NGSI-LD API ETSI GS CIM 009 V1.4.2, Annex A.3, p.183, 2021-04.

Module Attributes

`NID_PATTERN`	Regex pattern that matches a valid namespace identifier (regex.Pattern).
`URN_PATTERN`	Regex pattern that extracts NID and NSS from a full valid urn string(regex.Pattern).
`ENTITY_TYPE_PATTERN`	Regex pattern that extracts type from a NGSI-LD NSS following naming convention.(regex.Pattern).

Classes

Urn()

Helper class to handle NGSI-LD urn/uri and allow to work with unprefixed strings.

Exceptions

UrnError

Exception raised when parsing invalid urn/uri.

ngsildclient.utils.urn.ENTITY_TYPE_PATTERN = re.compile('^([^:]+):.*')#: Regex pattern that extracts type from a NGSI-LD NSS following naming convention.(regex.Pattern).

ngsildclient.utils.urn.NID_PATTERN = re.compile('^[0-9a-zA-Z\\-]+$')#: Regex pattern that matches a valid namespace identifier (regex.Pattern).

ngsildclient.utils.urn.URN_PATTERN = re.compile('^urn:(?P<nid>[0-9a-zA-Z\\-]+):(?P<nss>.+)$')#: Regex pattern that extracts NID and NSS from a full valid urn string(regex.Pattern).

class ngsildclient.utils.urn.Urn(fqn: str)[source]#

class ngsildclient.utils.urn.Urn(*, nss: str, nid: str = DEFAULT_NID)

Bases: object

Helper class to handle NGSI-LD urn/uri and allow to work with unprefixed strings.

property fqn: str#

Returns the fully-qualified name

Returns: the fully qualified name
Return type: str

Example

>>> from ngsildclient.utils.urn import Urn
>>> urn = Urn(nss="AirQualityObserved:RZ:Obsv4567")
>>> print(urn.fqn)
urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567

infertype()[source]#

Infer type.

Work only when following the naming convention urn:ngsi-ld:<type>:…

Returns: the inferred NGSI LD type if found
Return type: Optional[str]

static is_prefixed(value)[source]#

Check whether the given string is prefixed (URN scheme+NID)

Parameters: value (str) – the string value to be checked
Returns: True if the string value starts with the NGSI-LD u`urn:ngsi-ld:`
Return type: bool

Example

>>> from ngsildclient.utils.urn import Urn
>>> print(Urn.is_prefixed("urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567"))
True

static is_valid_nid(nid)[source]#

Check whether the given nid is a valid one

Parameters: nid (str) – the nid string to be checked
Returns: True if if the nid is valid
Return type: bool

Example

>>> from ngsildclient.utils.urn import Urn
>>> print(Urn.is_valid_nid("ngsi-ld"))
True
>>> print(Urn.is_valid_nid("ngsi+ld"))
False

static prefix(value)[source]#

Prefix a string with URN scheme+NID

Parameters: value (str) – the string to be prefixed
Returns: the string prefixed (if not already prefixed)
Return type: str

Example

>>> from ngsildclient.utils.urn import Urn
>>> print(Urn.prefix("AirQualityObserved:RZ:Obsv4567"))
urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567

static unprefix(value)[source]#

Remove the prefix (URN scheme+NID)

Parameters: value (str) – the string to be unprefixed
Returns: the string without the prefix
Return type: str

Example

>>> from ngsildclient.utils.urn import Urn
>>> print(Urn.unprefix("urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567"))
AirQualityObserved:RZ:Obsv4567

exception ngsildclient.utils.urn.UrnError[source]#

Bases: Exception

Exception raised when parsing invalid urn/uri.

with_traceback()#: Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.