VisibleString type

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

Creates VisibleString type or object.

VisibleString objects are immutable and duck-type Python 2 unicode or Python 3 str. When used in octet-stream context, VisibleString type assumes “us-ascii” encoding.

Parameters:
  • value (unicode, str, bytes or VisibleString object) – unicode object (Python 2) or string (Python 3), alternatively string (Python 2) or bytes (Python 3) representing octet-stream of serialized unicode string (note encoding parameter) or VisibleString class instance.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when VisibleString object is used in octet-stream context.
Raises:

pyasn1.error.PyAsn1Error – On constraint violation or bad initializer.

Note

The VisibleString type models a character string that can hold any “graphical” characters mixed with control ones to select particular alphabet.

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

Creates a copy of a VisibleString type or object.

Any parameters to the clone() method will replace corresponding properties of the VisibleString object.

Parameters:
  • value (unicode, str, bytes or VisibleString object) – unicode object (Python 2) or string (Python 3), alternatively string (Python 2) or bytes (Python 3) representing octet-stream of serialized unicode string (note encoding parameter) or VisibleString class instance.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when VisibleString object is used in octet-stream context.
Returns:

new instance of VisibleString type/value

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

Creates a copy of a VisibleString type or object.

Any parameters to the subtype() method will be added to the corresponding properties of the VisibleString object.

Parameters:
  • value (unicode, str, bytes or VisibleString object) – unicode object (Python 2) or string (Python 3), alternatively string (Python 2) or bytes (Python 3) representing octet-stream of serialized unicode string (note encoding parameter) or VisibleString class instance.
  • implicitTag (Tag) – Implicitly apply given ASN.1 tag object to caller’s TagSet, then use the result as new object’s ASN.1 tag(s).
  • explicitTag (Tag) – Explicitly apply given ASN.1 tag object to caller’s TagSet, then use the result as new object’s ASN.1 tag(s).
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when VisibleString object is used in octet-stream context.
Returns:

new instance of VisibleString type/value

tagSet = TagSet((), Tag(tagClass=0, tagFormat=0, tagId=26))

Default TagSet object for VisibleString objects

hasValue()

Indicate if VisibleString object represents ASN.1 value or ASN.1 type.

The PyASN1 type objects can only participate in types comparison and serve as a blueprint for serialization codecs to resolve ambiguous types.

The PyASN1 value objects can additionally participate to most of built-in Python operations.

Returns:boolTrue if object is ASN.1 value, False otherwise.
isSameTypeWith(other, matchTags=True, matchConstraints=True)

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

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

No Python inheritance relationship between PyASN1 objects is considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is VisibleString type, False otherwise.
isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine VisibleString 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.

No Python inheritance relationship between PyASN1 objects is considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is a subtype of VisibleString type, False otherwise.