models/piper_model.py

from piper import PiperVoice
import subprocess
import wave
import tempfile

VOICE_PATH = "voices/fr/fr_FR/siwis/medium/fr_FR-siwis-medium.onnx"

def generate(sentence):

    output_wav = tempfile.mktemp(
        suffix=".wav"
    )

    process = subprocess.Popen(
        [
            "piper",
            "--model",
            VOICE_PATH,
            "--output_file",
            output_wav
        ],
        stdin=subprocess.PIPE,
        text=True
    )

    process.communicate(sentence)

    return output_wav