我使用的是pyvona套餐（2016年7月3日起）。我安装了所有依赖项。当我第一次打电话给它时，它正常工作。但是，如果我再次运行该命令，它会给我本地未绑定的错误：
>>> import pyvona
>>> v = pyvona.create_voice('<key>', '<secret>')
>>> v.speak('hello')
>>> v.speak('hello')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python34\lib\site-packages\pyvona.py", line 159, in speak
channel.play(sound)
UnboundLocalError: local variable 'channel' referenced before assignment
>>>
这是pyvona.py脚本：
#!/usr/bin/env python
# encoding: utf-8
"""Pyvona : an IVONA python library
Author: Zachary Bears
Contact Email: bears.zachary@gmail.com
Note: Full operation of this library requires the requests and pygame libraries
"""
import datetime
import hashlib
import hmac
import json
import tempfile
import contextlib
import os
class PyvonaException(Exception):
pass
try:
import pygame
except ImportError:
pygame_available = False
else:
pygame_available = True
try:
import requests
requests.packages.urllib3.disable_warnings()
except ImportError:
msg = 'The requests library is essential for Pyvona operation. '
msg += 'Without it, Pyvona will not function correctly.'
raise PyvonaException(msg)
_amazon_date_format = '%Y%m%dT%H%M%SZ'
_date_format = '%Y%m%d'
def create_voice(access_key, secret_key):
"""Creates and returns a voice object to interact with
"""
return Voice(access_key, secret_key)
class Voice(object):
"""An object that contains all the required methods for interacting
with the IVONA text-to-speech system
"""
voice_name = None
language = None
gender = None
speech_rate = None
sentence_break = None
paragraph_break = None
_codec = "ogg"
region_options = {
'us-east': 'us-east-1',
'us-west': 'us-west-2',
'eu-west': 'eu-west-1',
}
access_key = None
secret_key = None
algorithm = 'AWS4-HMAC-SHA256'
signed_headers = 'content-type;host;x-amz-content-sha256;x-amz-date'
_region = None
_host = None
@property
def region(self):
return self._region
@region.setter
def region(self, region_name):
self._region = self.region_options.get(region_name, 'us-east-1')
self._host = 'tts.{}.ivonacloud.com'.format(self._region)
@property
def codec(self):
return self._codec
@codec.setter
def codec(self, codec):
if codec not in ["mp3", "ogg"]:
raise PyvonaException(
"Invalid codec specified. Please choose 'mp3' or 'ogg'")
self._codec = codec
@contextlib.contextmanager
def use_ogg_codec(self):
current_codec = self.codec
self.codec = "ogg"
try:
yield
finally:
self.codec = current_codec
def fetch_voice_ogg(self, text_to_speak, filename):
"""Fetch an ogg file for given text and save it to the given file name
"""
with self.use_ogg_codec():
self.fetch_voice(text_to_speak, filename)
def fetch_voice(self, text_to_speak, filename):
"""Fetch a voice file for given text and save it to the given file name
"""
file_extension = ".{codec}".format(codec=self.codec)
filename += file_extension if not filename.endswith(
file_extension) else ""
with open(filename, 'wb') as f:
self.fetch_voice_fp(text_to_speak, f)
def fetch_voice_fp(self, text_to_speak, fp):
"""Fetch a voice file for given text and save it to the given file pointer
"""
r = self._send_amazon_auth_packet_v4(
'POST', 'tts', 'application/json', '/CreateSpeech', '',
self._generate_payload(text_to_speak), self._region, self._host)
if r.content.startswith(b'{'):
raise PyvonaException('Error fetching voice: {}'.format(r.content))
else:
fp.write(r.content)
def speak(self, text_to_speak, use_cache=False):
"""Speak a given text
"""
if not pygame_available:
raise PyvonaException(
"Pygame not installed. Please install to use speech.")
if not pygame.mixer.get_init():
pygame.mixer.init()
channel = pygame.mixer.Channel(5)
if use_cache is False:
with tempfile.SpooledTemporaryFile() as f:
with self.use_ogg_codec():
self.fetch_voice_fp(text_to_speak, f)
f.seek(0)
sound = pygame.mixer.Sound(f)
else:
cache_f = hashlib.md5(text_to_speak).hexdigest() + '.ogg'
speech_cache_dir = os.getcwd() + '/speech_cache/'
if not os.path.isdir(speech_cache_dir):
os.makedirs(speech_cache_dir)
if not os.path.isfile(speech_cache_dir + cache_f):
with self.use_ogg_codec():
self.fetch_voice(text_to_speak, 'speech_cache/' + cache_f)
f = speech_cache_dir + cache_f
sound = pygame.mixer.Sound(f)
channel.play(sound)
while channel.get_busy():
pass
def list_voices(self):
"""Returns all the possible voices
"""
r = self._send_amazon_auth_packet_v4(
'POST', 'tts', 'application/json', '/ListVoices', '', '',
self._region, self._host)
return r.json()
def _generate_payload(self, text_to_speak):
return json.dumps({
'Input': {
"Type":"application/ssml+xml",
'Data': text_to_speak
},
'OutputFormat': {
'Codec': self.codec.upper()
},
'Parameters': {
'Rate': self.speech_rate,
'SentenceBreak': self.sentence_break,
'ParagraphBreak': self.paragraph_break
},
'Voice': {
'Name': self.voice_name,
'Language': self.language,
'Gender': self.gender
}
})
def _send_amazon_auth_packet_v4(self, method, service, content_type,
canonical_uri, canonical_querystring,
request_parameters, region, host):
"""Send a packet to a given amazon server using Amazon's signature Version 4,
Returns the resulting response object
"""
# Create date for headers and the credential string
t = datetime.datetime.utcnow()
amazon_date = t.strftime(_amazon_date_format)
date_stamp = t.strftime(_date_format)
# Step 1: Create canonical request
payload_hash = self._sha_hash(request_parameters)
canonical_headers = 'content-type:{}\n'.format(content_type)
canonical_headers += 'host:{}\n'.format(host)
canonical_headers += 'x-amz-content-sha256:{}\n'.format(payload_hash)
canonical_headers += 'x-amz-date:{}\n'.format(amazon_date)
canonical_request = '\n'.join([
method, canonical_uri, canonical_querystring, canonical_headers,
self.signed_headers, payload_hash])
# Step 2: Create the string to sign
credential_scope = '{}/{}/{}/aws4_request'.format(
date_stamp, region, service)
string_to_sign = '\n'.join([
self.algorithm, amazon_date, credential_scope,
self._sha_hash(canonical_request)])
# Step 3: Calculate the signature
signing_key = self._get_signature_key(
self.secret_key, date_stamp, region, service)
signature = hmac.new(
signing_key, string_to_sign.encode('utf-8'),
hashlib.sha256).hexdigest()
# Step 4: Create the signed packet
endpoint = 'https://{}{}'.format(host, canonical_uri)
authorization_header = '{} Credential={}/{}, ' +\
'SignedHeaders={}, Signature={}'
authorization_header = authorization_header.format(
self.algorithm, self.access_key, credential_scope,
self.signed_headers, signature)
headers = {
'Host': host,
'Content-type': content_type,
'X-Amz-Date': amazon_date,
'Authorization': authorization_header,
'x-amz-content-sha256': payload_hash,
'Content-Length': len(request_parameters)
}
# Send the packet and return the response
return requests.post(endpoint, data=request_parameters,
headers=headers)
def _sha_hash(self, to_hash):
return hashlib.sha256(to_hash.encode('utf-8')).hexdigest()
def _sign(self, key, msg):
return hmac.new(key, msg.encode('utf-8'), hashlib.sha256).digest()
def _get_signature_key(self, key, date_stamp, region_name, service_name):
k_date = self._sign(('AWS4{}'.format(key)).encode('utf-8'), date_stamp)
k_region = self._sign(k_date, region_name)
k_service = self._sign(k_region, service_name)
k_signing = self._sign(k_service, 'aws4_request')
return k_signing
def __init__(self, access_key, secret_key):
"""Set initial voice object parameters
"""
self.region = 'us-east'
self.voice_name = 'Brian'
self.access_key = access_key
self.secret_key = secret_key
self.speech_rate = 'medium'
self.sentence_break = 400
self.paragraph_break = 650
非常感谢任何帮助。
答案 0 :(得分：0)
能够通过添加以下内容找到解决方法：
pygame.mixer.init（）
channel = pygame.mixer.Channel（5）
定义说话功能后立即：
def speak（self，text_to_speak，use_cache = False）：
def speak(self, text_to_speak, use_cache=False):
"""Speak a given text
"""
pygame.mixer.init()
channel = pygame.mixer.Channel(5)
答案 1 :(得分：0)
通常，UnboundLocalError与Python Scopes and NameSpaces中的范围和命名空间相关， 但在你的情况下： 在功能speak（）您在代码中创建频道
if not pygame.mixer.get_init():
pygame.mixer.init()
channel = pygame.mixer.Channel(5)
如果此代码不执行，则通道不会绑定到任何对象。
例如，您可以通过以下代码示例检查此情况：
def test_if():
if True:
# Bound
channel_1 = "Channel_1"
if False:
# Not bound
channel_2 = "Channel_2"
print(channel_1)
print(channel_2)
test_if()