BMPString type

class pyasn1.type.char.BMPString(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Creates BMPString schema or value object.

BMPString class is based on SimpleAsn1Type, its objects are immutable and duck-type bytes. When used in octet-stream context, BMPString type assumes “utf-16-be” encoding.

Keyword Arguments:

  • value (str, bytes or BMPString object) – str, alternatively bytes representing octet-stream of serialised unicode string (note encoding parameter) or BMPString class instance. If value is not given, schema object will be created.

  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)

  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s). Constraints verification for BMPString type occurs automatically on object instantiation.

  • encoding (str) – Unicode codec ID to encode/decode str the payload when BMPString object is used in octet-stream context.

Raises:

ValueConstraintError, PyAsn1Error – On constraint violation or bad initializer.

Note

The BMPString type models a Unicode (ISO10646-1) character string implicitly serialised into UTF-16 big endian.

clone(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Create a modified version of BMPString schema or value object.

The clone() method accepts the same set arguments as BMPString class takes on instantiation except that all arguments of the clone() method are optional.

Whatever arguments are supplied, they are used to create a copy of self taking precedence over the ones used to instantiate self.

Note

Due to the immutable nature of the BMPString object, if no arguments are supplied, no new BMPString object will be created and self will be returned instead.

subtype(value=NoValue(), implicitTag=Tag(), explicitTag=Tag(), subtypeSpec=ConstraintsIntersection(), encoding='us-ascii')

Create a specialization of BMPString schema or value object.

The subtype relationship between ASN.1 types has no correlation with subtype relationship between Python types. ASN.1 type is mainly identified by its tag(s) (TagSet) and value range constraints (ConstraintsIntersection). These ASN.1 type properties are implemented as BMPString attributes.

The subtype() method accepts the same set arguments as BMPString class takes on instantiation except that all parameters of the subtype() method are optional.

With the exception of the arguments described below, the rest of supplied arguments they are used to create a copy of self taking precedence over the ones used to instantiate self.

The following arguments to subtype() create a ASN.1 subtype out of BMPString type:

Other Parameters:

  • implicitTag (Tag) – Implicitly apply given ASN.1 tag object to self’s TagSet, then use the result as new object’s ASN.1 tag(s).

  • explicitTag (Tag) – Explicitly apply given ASN.1 tag object to self’s TagSet, then use the result as new object’s ASN.1 tag(s).

  • subtypeSpec (ConstraintsIntersection) – Add ASN.1 constraints object to one of the self’s, then use the result as new object’s ASN.1 constraints.

Returns:

new instance of BMPString schema or value object

Note

Due to the immutable nature of the BMPString object, if no arguments are supplied, no new BMPString object will be created and self will be returned instead.

tagSet = <TagSet object, tags 0:0:30>

Set (on class, not on instance) or return a TagSet object representing ASN.1 tag(s) associated with BMPString type.

property isValue

Indicate that BMPString object represents ASN.1 value.

If isValue is False then this object represents just ASN.1 schema.

If isValue is True then, in addition to its ASN.1 schema features, this object can also be used like a Python built-in object (e.g. int, str, dict etc.).

Returns:

bool – False if object represents just ASN.1 schema. True if object represents ASN.1 schema and can be used as a normal value.

Note

There is an important distinction between PyASN1 schema and value objects. The PyASN1 schema objects can only participate in ASN.1 schema-related operations (e.g. defining or testing the structure of the data). Most obvious uses of ASN.1 schema is to guide serialisation codecs whilst encoding/decoding serialised ASN.1 contents.

The PyASN1 value objects can additionally participate in many operations involving regular Python objects (e.g. arithmetic, comprehension etc).

isSameTypeWith(other, matchTags=True, matchConstraints=True)

Examine BMPString type for equality with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

Python class inheritance relationship is NOT considered.

Parameters:

other (a pyasn1 type object) – Class instance representing ASN.1 type.

Returns:

bool – True if other is BMPString type, False otherwise.

isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine BMPString type for subtype relationship with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

Python class inheritance relationship is NOT considered.

Parameters:

other (a pyasn1 type object) – Class instance representing ASN.1 type.

Returns:

bool – True if other is a subtype of BMPString type, False otherwise.

property effectiveTagSet

For BMPString type is equivalent to tagSet

property tagMap

Return a TagMap object mapping ASN.1 tags to ASN.1 objects within callee object.