BitString type

class pyasn1.type.univ.BitString(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), namedValues=NamedValues(), binValue=NoValue(), hexValue=NoValue())

Create BitString type or object.

BitString objects are immutable and duck-type both Python tuple (as a tuple of bits) and int objects.

Parameters:
  • value (int, str or BitString object) – Python integer or string literal representing binary or hexadecimal number or sequence of integer bits or BitString object.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • namedValues (NamedValues) – Object representing non-default symbolic aliases for numbers
  • binValue (str) – Binary string initializer to use instead of the value. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer to use instead of the value. Example: ‘DEADBEEF’.
Raises:

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

Note

The BitString type models an arbitrary sequence of bits.

clone(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), namedValues=NamedValues(), binValue=NoValue(), hexValue=NoValue())

Create a copy of a BitString type or object.

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

Parameters:
  • value (int, str or BitString object) – Initialization value to pass to new ASN.1 object instead of inheriting one from the caller.
  • tagSet (TagSet) – Object representing ASN.1 tag(s) to use in new object instead of inheriting from the caller
  • subtypeSpec (ConstraintsIntersection) – Object representing ASN.1 subtype constraint(s) to use in new object instead of inheriting from the caller
  • namedValues (NamedValues) – Class instance representing BitString type enumerations
  • binValue (str) – Binary string initializer to use instead of the value. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer to use instead of the value. Example: ‘DEADBEEF’.
Returns:

new instance of BitString type/value

subtype(value=NoValue(), implicitTag=Tag(), explicitTag=Tag(), subtypeSpec=ConstraintsIntersection(), namedValues=NamedValues(), binValue=NoValue(), hexValue=NoValue())

Create a copy of a BitString type or object.

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

Parameters:
  • value (int, str or BitString object) – Initialization value to pass to new ASN.1 object instead of inheriting one from the caller.
  • 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) – Add ASN.1 constraints object to one of the caller, then use the result as new object’s ASN.1 constraints.
  • namedValues (NamedValues) – Add given object representing symbolic aliases for numbers to one of the caller, then use the result as new object’s named numbers.
  • binValue (str) – Binary string initializer to use instead of the value. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer to use instead of the value. Example: ‘DEADBEEF’.
Returns:

new instance of BitString type/value

tagSet = TagSet((), Tag(tagClass=0, tagFormat=0, tagId=3))

Default TagSet object for BitString objects

subtypeSpec = ConstraintsIntersection()

Default ConstraintsIntersection object imposing constraints on initialization values.

asNumbers()

Get BitString value as a sequence of 8-bit integers.

If BitString object length is not a multiple of 8, result will be left-padded with zeros.

asOctets()

Get BitString value as a sequence of octets.

If BitString object length is not a multiple of 8, result will be left-padded with zeros.

asInteger()

Get BitString value as a single integer value.

asBinary()

Get BitString value as a text string of bits.

hasValue()

Indicate if BitString 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 BitString 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 BitString type, False otherwise.
isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine BitString 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 BitString type, False otherwise.