Codec API¶
This module defines the Codec base class, a common interface for
all codec classes.
Codec classes must implement Codec.encode() and Codec.decode()
methods. Inputs to and outputs from these methods may be any Python object
exporting a contiguous buffer via the new-style Python protocol.
Codec classes must implement a Codec.get_config() method,
which must return a dictionary holding all configuration parameters
required to enable encoding and decoding of data. The expectation is that
these configuration parameters will be stored or communicated separately
from encoded data, and thus the codecs do not need to store all encoding
parameters within the encoded data. For broad compatibility,
the configuration object must contain only JSON-serializable values. The
configuration object must also contain an ‘id’ field storing the codec
identifier (see below).
Codec classes must implement a Codec.from_config() class method,
which will return an instance of the class initialized from a configuration
object.
Finally, codec classes must set a codec_id class-level attribute. This must be a string. Two different codec classes may set the same value for the codec_id attribute if and only if they are fully compatible, meaning that (1) configuration parameters are the same, and (2) given the same configuration, one class could correctly decode data encoded by the other and vice versa.
- class numcodecs.abc.Codec[source]¶
Codec abstract base class.
- codec_id = None¶
Codec identifier.
- abstract encode(buf)[source]¶
Encode data in buf.
- Parameters:
- bufbuffer-like
Data to be encoded. May be any object supporting the new-style buffer protocol.
- Returns:
- encbuffer-like
Encoded data. May be any object supporting the new-style buffer protocol.
- abstract decode(buf, out=None)[source]¶
Decode data in buf.
- Parameters:
- bufbuffer-like
Encoded data. May be any object supporting the new-style buffer protocol.
- outbuffer-like, optional
Writeable buffer to store decoded data. N.B. if provided, this buffer must be exactly the right size to store the decoded data.
- Returns:
- decbuffer-like
Decoded data. May be any object supporting the new-style buffer protocol.