21.5. wave — Read and write WAV files - Python 2.7.18 documentation 编辑

Source code: Lib/wave.py

The wave module provides a convenient interface to the WAV sound format. It does not support compression/decompression, but it does support mono/stereo.

The wave module defines the following function and exception:

wave.open(file[, mode])

If file is a string, open the file by that name, otherwise treat it as a seekable file-like object. mode can be any of

'r', 'rb': Read only mode.
'w', 'wb': Write only mode.

Note that it does not allow read/write WAV files.

A mode of 'r' or 'rb' returns a Wave_read object, while a mode of 'w' or 'wb' returns a Wave_write object. If mode is omitted and a file-like object is passed as file, file.mode is used as the default value for mode (the 'b' flag is still added if necessary).

If you pass in a file-like object, the wave object will not close it when its close() method is called; it is the caller’s responsibility to close the file object.

wave.openfp(file, mode): A synonym for open(), maintained for backwards compatibility.

exception wave.Error: An error raised when something is impossible because it violates the WAV specification or hits an implementation deficiency.

21.5.1. Wave_read Objects

Wave_read objects, as returned by open(), have the following methods:

Wave_read.close(): Close the stream if it was opened by wave, and make the instance unusable. This is called automatically on object collection.

Wave_read.getnchannels(): Returns number of audio channels (1 for mono, 2 for stereo).

Wave_read.getsampwidth(): Returns sample width in bytes.

Wave_read.getframerate(): Returns sampling frequency.

Wave_read.getnframes(): Returns number of audio frames.

Wave_read.getcomptype(): Returns compression type ('NONE' is the only supported type).

Wave_read.getcompname(): Human-readable version of getcomptype(). Usually 'not compressed' parallels 'NONE'.

Wave_read.getparams(): Returns a tuple (nchannels, sampwidth, framerate, nframes, comptype, compname), equivalent to output of the get*() methods.

Wave_read.readframes(n): Reads and returns at most n frames of audio, as a string of bytes.

Wave_read.rewind(): Rewind the file pointer to the beginning of the audio stream.

The following two methods are defined for compatibility with the aifc module, and don’t do anything interesting.

Wave_read.getmarkers(): Returns None.

Wave_read.getmark(id): Raise an error.

The following two methods define a term “position” which is compatible between them, and is otherwise implementation dependent.

Wave_read.setpos(pos): Set the file pointer to the specified position.

Wave_read.tell(): Return current file pointer position.

21.5.2. Wave_write Objects

Wave_write objects, as returned by open(), have the following methods:

Wave_write.close(): Make sure nframes is correct, and close the file if it was opened by wave. This method is called upon object collection.

Wave_write.setnchannels(n): Set the number of channels.

Wave_write.setsampwidth(n): Set the sample width to n bytes.

Wave_write.setframerate(n): Set the frame rate to n.

Wave_write.setnframes(n): Set the number of frames to n. This will be changed later if more frames are written.

Wave_write.setcomptype(type, name): Set the compression type and description. At the moment, only compression type NONE is supported, meaning no compression.

Wave_write.setparams(tuple): The tuple should be (nchannels, sampwidth, framerate, nframes, comptype, compname), with values valid for the set*() methods. Sets all parameters.