Creating Objects

As shown in the Hello World section, to create a new py4pd object you must use the subclass puredata.NewObject, define the object’s name, and save it in a folder using the pattern <object_name>.pd_py. To enable object creation, you must always import the puredata module, which is only available when the script .pd_py is loaded via py4pd.

NewObject Class

All PureData Python objects are created as subclasses from the base class puredata.NewObject.

import puredata as pd

class pymetro(pd.NewObject):
    name: str = "pymetro" # object name, must be exactly the same as the file name without extension (pymetro.pd_py)

    def __init__(self, args):
        # Object initializer
        pass

Object Attributes

From the class initializer (__init__), you need to define some object attributes. Like self.inlets, self.outlets and options attributes (like clocks, receivers, etc).

• self.inlets: Can be an integer (number of inlets) or a Tuple specifying inlet types (puredata.SIGNAL or puredata.DATA), where each element in the tuple defines the type of the inlet at the corresponding index.

• self.outlets: Can be an integer (number of outlets) or a Tuple specifying outlet types (puredata.SIGNAL or puredata.DATA), where each element in the tuple defines the type of the outlet at the corresponding index.

pd.NewObject Methods

self.logpost

Post things on PureData console.

self.error

Print error, same as logpost with error level.

self.out

Output data to the objecta.

self.tabwrite

Write Tuple of numbers in the pd array.

self.tabread

Read table from pd, returns a tuple.

self.reload

Reload the object.

Clocks

class pymetro(pd.NewObject):
    name: str = "pymetro"

    def __init__(self, args):
        self.inlets = 2
        self.outlets = 1
        self.metro = self.new_clock(self.tick)

self.new_clock

Clock can be created using the self.new_clock method, which returns a puredata.Clock object. new_clock accepts a function as an argument, which will be executed when the clock ticks. In the above example, self.metro will have the methods:

delay

Set a delay in milliseconds to execute function (in this case, self.tick).

set

TODO:

unset

TODO:

Receivers

self.new_receiver

Extra puredata Methods

pd.post

Post a message to PureData without being possible to detect the object (for example, for credits in objects).

pd.hasgui

Returns if PureData has a GUI interface.

Complet Examples

Here some examples of objects:

Tradicional Objects

import puredata as pd


class pymetro(pd.NewObject):
    name: str = "pymetro"

    def __init__(self, args):
        self.inlets = 2
        self.outlets = 1
        self.toggle = False
        if len(args) > 0:
            self.time = float(args[0])
        else:
            self.time = 1000
        self.metro = self.new_clock(self.tick)
        self.args = args

    def in_2_float(self, f: float):
        self.time = f

    def in_1_float(self, f: float):
        if f:
            self.toggle = True
            self.tick()
        else:
            self.metro.unset()
            self.toggle = False

    def in_1_reload(self, args: list):
        self.reload()

    def tick(self):
        if self.toggle:
            self.metro.delay(self.time)
        self.out(0, pd.SYMBOL, "test238")

Python Data

Audio Objects

Graphical Objects