music.GenericPeal¶

class music.GenericPeal[source]¶

Bases: object

A collection of named peals that can be acted on a domain.

The base for the named-peal model: peals maps a name to a list of permutations, and act applies one of them by name. Peals works that way and inherits this.

music.PlainChanges deliberately does not. It is built from one peal rather than holding several, so its act acts that peal and takes the domain first – act(domain) rather than act(name, domain). The two are different operations that happen to share a verb.

Attributes:

nelementsint: The number of elements in the domain.
pealsdict: A dictionary containing the peals and their corresponding actions.
acted_pealsdict: A dictionary containing the acted peals and their results.
domainlist: The domain on which the peals are acted.

Methods

`act`(peal[, domain])	Acts a specific peal on the specified domain.
`act_all`([domain])	Acts all peals on the specified domain.

Examples

>>> peal = GenericPeal()
>>> peal.peals = {"rows": PlainChanges(4).peal_direct[:4]}
>>> rows = peal.act("rows", domain=[220, 275, 330, 440])
>>> len(rows), len(rows[0])
(4, 4)

nelements is what a default domain would be built from, so a bare GenericPeal needs the domain passed:

>>> peal.act("rows")
Traceback (most recent call last):
    ...
ValueError: nelements has not been set, ...

__init__()[source]¶: Initializes a GenericPeal object.

Methods

`__init__`()	Initializes a GenericPeal object.
`act`(peal[, domain])	Acts a specific peal on the specified domain.
`act_all`([domain])	Acts all peals on the specified domain.

Attributes

`peals`	name -> list of permutations.
`acted_peals`

peals: dict¶: name -> list of permutations. Empty rather than None: a collection with nothing in it is what an unpopulated one is, and act() refuses to run on either.

acted_peals: dict¶

act(peal, domain=None)[source]¶

Acts a specific peal on the specified domain.

Parameters:

pealstr: The name of the peal to act.
domainlist, optional: The domain on which to act the peal. Defaults to None.

Returns:

list: The result of acting the peal on the specified domain.

Raises:

ValueError: If no peals are defined, no domain is given and nelements is not set, or the domain’s length is not the number of elements the peal permutes.
KeyError: If no peal goes by peal.

act_all(domain=None)[source]¶

Acts all peals on the specified domain.

Parameters:

domainlist, optional: The domain on which to act the peals. Defaults to None.

Raises:

ValueError: As act() raises it.