Real type

class pyasn1.type.univ.Real(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection())

Create Real type or object.

Real objects are immutable and duck-type Python float objects. Additionally, Real objects behave like a tuple in which case its elements are mantissa, base and exponent.

Parameters:
  • value (tuple, float or Real object) – Python sequence of int (representing mantissa, base and exponent) or float instance or Real class instance.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
Raises:

: :py:class:`pyasn1.error.PyAsn1Error` – On constraint violation or bad initializer.

Note

The Real type models a rational number of arbitrary precision.

clone(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection())

Create a copy of a Real type or object.

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

Parameters:
  • value (tuple, float or Real 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
Returns:

new instance of Real type/value
subtype(value=NoValue(), implicitTag=Tag(), explicitTag=Tag(), subtypeSpec=ConstraintsIntersection())

Create a copy of a Real type or object.

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

Parameters:
  • value (tuple, float or Real 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) – Object representing ASN.1 subtype constraint(s) to use in new object instead of inheriting from the caller
Returns:

new instance of Real type/value
tagSet = TagSet((), Tag(tagClass=0, tagFormat=0, tagId=9))

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

subtypeSpec = ConstraintsIntersection()

Set (on class, not on instance) or return a ConstraintsIntersection object imposing constraints on Real type initialization values.

isPlusInf

Indicate PLUS-INFINITY object value

Returns:bool – True if calling object represents plus infinity or False otherwise.
isMinusInf

Indicate MINUS-INFINITY object value

Returns:bool – True if calling object represents minus infinity or False otherwise.
effectiveTagSet

For Real type is equivalent to tagSet

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

Examine Real 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:bool – True if other is Real type, False otherwise.
isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine Real 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:bool – True if other is a subtype of Real type, False otherwise.
isValue

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

In other words, if isValue is True, then the ASN.1 object is initialized.

Returns:bool – True if object represents ASN.1 value and type, False if object represents just ASN.1 type.

Note

There is an important distinction between PyASN1 type and value objects. The PyASN1 type objects can only participate in ASN.1 type operations (subtyping, comparison etc) and serve as a blueprint for serialization codecs to resolve ambiguous types.

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

tagMap

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