Python SDK

Prerequisites

Before you use the SDK, read the API reference. For more information, see API reference.

Download and installation

1. Download the Python SDK.

   You can obtain the Python SDK from GitHub or download streamInputTts-github-python directly.

2. Install the SDK dependencies.

   Go to the SDK root directory and run the following command to install the dependencies:

   python -m pip install -r requirements.txt

3. Install the SDK.

   After the dependencies are installed, run the following command to install the SDK:

   python -m pip install .

4. After installation, import the SDK using the following code:

   # -*- coding: utf-8 -*-
   import nls

Multi-threading and concurrency

In CPython, the global interpreter lock allows only one thread to execute Python code at a time, although some performance-oriented libraries can remove this limitation. To better utilize the compute resources of a multi-core computer, use multiprocessing or concurrent.futures.ProcessPoolExecutor. If you want to run multiple I/O-intensive tasks concurrently, multi-threading is still a suitable model.

If a single interpreter has too many threads, switching between them causes significant overhead and may lead to SDK errors. We recommend that you do not use more than 200 threads. Instead, use the multiprocessing technique or manually create multiple interpreters using a script.

Key interfaces

The NlsSpeechSynthesizer class is used for speech synthesis. Its core methods are as follows:

• Return value: None

Code examples

import time
import threading
import sys

import nls

URL="wss://nls-gateway-cn-shanghai.aliyuncs.com/ws/v1"
TOKEN="yourToken"  # For more information about how to obtain a token, see https://help.aliyun.com/document_detail/450255.html
APPKEY="yourAppkey"       # To obtain an AppKey, go to the console: https://nls-portal.console.aliyun.com/applist



TEXT='Da Zhuang was about to pick the petals, but Ali and A Qiang suddenly started fighting. Ali took a pistol and shot at A Qiang by the tree trunk. After two gunshots, A Qiang fell directly into the water.'

# The following code repeatedly performs speech synthesis based on the preceding TEXT.
class TestTts:
    def __init__(self, tid, test_file):
        self.__th = threading.Thread(target=self.__test_run)
        self.__id = tid
        self.__test_file = test_file
   
    def start(self, text):
        self.__text = text
        self.__f = open(self.__test_file, "wb")
        self.__th.start()
    
    def test_on_metainfo(self, message, *args):
        print("on_metainfo message=>{}".format(message))  

    def test_on_error(self, message, *args):
        print("on_error args=>{}".format(args))

    def test_on_close(self, *args):
        print("on_close: args=>{}".format(args))
        try:
            self.__f.close()
        except Exception as e:
            print("close file failed since:", e)

    def test_on_data(self, data, *args):
        try:
            self.__f.write(data)
        except Exception as e:
            print("write data failed:", e)

    def test_on_completed(self, message, *args):
        print("on_completed:args=>{} message=>{}".format(args, message))


    def __test_run(self):
      	print("thread:{} start..".format(self.__id))
      	tts = nls.NlsSpeechSynthesizer(url=URL,
      	      	      	      	       token=TOKEN,
      	      	      	      	       appkey=APPKEY,
      	      	      	      	       on_metainfo=self.test_on_metainfo,
      	      	      	      	       on_data=self.test_on_data,
      	      	      	      	       on_completed=self.test_on_completed,
      	      	      	      	       on_error=self.test_on_error,
      	      	      	      	       on_close=self.test_on_close,
      	      	      	      	       callback_args=[self.__id])
      	print("{}: session start".format(self.__id))
      	r = tts.start(self.__text, voice="ailun")
      	print("{}: tts done with result:{}".format(self.__id, r))

def multiruntest(num=500):
    for i in range(0, num):
        name = "thread" + str(i)
        t = TestTts(name, "tests/test_tts.pcm")
        t.start(TEXT)

nls.enableTrace(True)
multiruntest(1)