UnitInterval

class cometa.common.unit_interval.UnitInterval(ptr)[source]

Bases: object

Represents a rational number as a ratio of two integers.

Unit intervals are used throughout Cardano to represent fractional values such as protocol parameters (e.g., treasury cut, pool pledge influence). They are serialized as Rational Numbers (CBOR Tag 30).

The value of a unit interval is the numerator divided by the denominator.

Example

>>> interval = UnitInterval(1, 4)  # Represents 0.25
>>> interval.to_float()
0.25

__init__(ptr)[source]

Return type:: None

__enter__()[source]

Return type:: UnitInterval

__exit__(exc_type, exc_val, exc_tb)[source]

Return type:: None

__repr__()[source]

Return repr(self).

Return type:: str

classmethod new(numerator, denominator)[source]

Creates a new unit interval from a numerator and denominator.

Parameters:

numerator (int) – The numerator of the fraction.
denominator (int) – The denominator of the fraction (must not be zero).

Returns:

A new UnitInterval instance.

Raises:

CardanoError – If creation fails (e.g., zero denominator).

Return type:

UnitInterval

Example

>>> interval = UnitInterval.new(3, 4)  # Represents 0.75

classmethod from_float(value)[source]

Creates a unit interval from a floating-point value.

The float is converted to a rational approximation with appropriate numerator and denominator values.

Parameters:: value (float) – The floating-point value to convert.
Returns:: A new UnitInterval approximating the given value.
Raises:: CardanoError – If creation fails.
Return type:: UnitInterval

Example

>>> interval = UnitInterval.from_float(0.25)
>>> interval.numerator
1
>>> interval.denominator
4

classmethod from_cbor(reader)[source]

Deserializes a UnitInterval from CBOR data.

Parameters:: reader (CborReader) – A CborReader positioned at the unit interval data.
Returns:: A new UnitInterval deserialized from the CBOR data.
Raises:: CardanoError – If deserialization fails.
Return type:: UnitInterval

property numerator: int: Returns the numerator of the unit interval.

property denominator: int: Returns the denominator of the unit interval.

to_float()[source]

Converts the unit interval to a floating-point value.

Returns:: The decimal value of the fraction (numerator / denominator).
Return type:: float

Example

>>> interval = UnitInterval.new(1, 4)
>>> interval.to_float()
0.25

to_cbor(writer)[source]

Serializes the unit interval to CBOR format.

Parameters:: writer (CborWriter) – A CborWriter to write the serialized data to.
Raises:: CardanoError – If serialization fails.
Return type:: None

to_cip116_json(writer)[source]

Converts this object to CIP-116 compliant JSON representation.

CIP-116 defines a standard JSON format for Cardano data structures.

Parameters:: writer (JsonWriter) – A JsonWriter to write the serialized data to.
Raises:: CardanoError – If conversion fails.
Return type:: None

__float__()[source]

Returns the floating-point representation.

Return type:: float

__eq__(other)[source]

Checks equality with another UnitInterval.

Parameters:: other (object)
Return type:: bool

__hash__()[source]

Returns a Python hash for use in sets and dicts.

Return type:: int

__str__()[source]

Returns a string representation of the unit interval.

Return type:: str