我尝试导入最先进的EfficientNet模型（pytorch实现）：
from efficientnet_pytorch import EfficientNet
import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np
import matplotlib.pyplot as plt
from torchvision.transforms import transforms as T
import torchvision
import torch.optim as optim
model = EfficientNet.from_pretrained('efficientnet-b0')
下载模型时出现了这样的错误链：
Downloading: "https://github.com/lukemelas/EfficientNet-PyTorch/releases/download/1.0/efficientnet-b0-355c32eb.pth" to /Users/telaust/.cache/torch/checkpoints/efficientnet-b0-355c32eb.pth
---------------------------------------------------------------------------
TimeoutError Traceback (most recent call last)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in do_open(self, http_class, req, **http_conn_args)
1316 h.request(req.get_method(), req.selector, req.data, headers,
-> 1317 encode_chunked=req.has_header('Transfer-encoding'))
1318 except OSError as err: # timeout error
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in request(self, method, url, body, headers, encode_chunked)
1228 """Send a complete request to the server."""
-> 1229 self._send_request(method, url, body, headers, encode_chunked)
1230
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in _send_request(self, method, url, body, headers, encode_chunked)
1274 body = _encode(body, 'body')
-> 1275 self.endheaders(body, encode_chunked=encode_chunked)
1276
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in endheaders(self, message_body, encode_chunked)
1223 raise CannotSendHeader()
-> 1224 self._send_output(message_body, encode_chunked=encode_chunked)
1225
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in _send_output(self, message_body, encode_chunked)
1015 del self._buffer[:]
-> 1016 self.send(msg)
1017
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in send(self, data)
955 if self.auto_open:
--> 956 self.connect()
957 else:
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in connect(self)
1383
-> 1384 super().connect()
1385
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py in connect(self)
927 self.sock = self._create_connection(
--> 928 (self.host,self.port), self.timeout, self.source_address)
929 self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/socket.py in create_connection(address, timeout, source_address)
726 if err is not None:
--> 727 raise err
728 else:
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/socket.py in create_connection(address, timeout, source_address)
715 sock.bind(source_address)
--> 716 sock.connect(sa)
717 # Break explicitly a reference cycle
TimeoutError: [Errno 60] Operation timed out
During handling of the above exception, another exception occurred:
URLError Traceback (most recent call last)
<ipython-input-5-5e9bdf5b3e02> in <module>
----> 1 model = EfficientNet.from_pretrained('efficientnet-b0')
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/efficientnet_pytorch/model.py in from_pretrained(cls, model_name, advprop, num_classes, in_channels)
209 def from_pretrained(cls, model_name, advprop=False, num_classes=1000, in_channels=3):
210 model = cls.from_name(model_name, override_params={'num_classes': num_classes})
--> 211 load_pretrained_weights(model, model_name, load_fc=(num_classes == 1000), advprop=advprop)
212 if in_channels != 3:
213 Conv2d = get_same_padding_conv2d(image_size = model._global_params.image_size)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/efficientnet_pytorch/utils.py in load_pretrained_weights(model, model_name, load_fc, advprop)
325 # AutoAugment or Advprop (different preprocessing)
326 url_map_ = url_map_advprop if advprop else url_map
--> 327 state_dict = model_zoo.load_url(url_map_[model_name])
328 if load_fc:
329 model.load_state_dict(state_dict)
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/torch/hub.py in load_state_dict_from_url(url, model_dir, map_location, progress, check_hash)
490 sys.stderr.write('Downloading: "{}" to {}\n'.format(url, cached_file))
491 hash_prefix = HASH_REGEX.search(filename).group(1) if check_hash else None
--> 492 download_url_to_file(url, cached_file, hash_prefix, progress=progress)
493
494 # Note: extractall() defaults to overwrite file if exists. No need to clean up beforehand.
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/torch/hub.py in download_url_to_file(url, dst, hash_prefix, progress)
389 # We use a different API for python2 since urllib(2) doesn't recognize the CA
390 # certificates in older Python
--> 391 u = urlopen(url)
392 meta = u.info()
393 if hasattr(meta, 'getheaders'):
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in urlopen(url, data, timeout, cafile, capath, cadefault, context)
220 else:
221 opener = _opener
--> 222 return opener.open(url, data, timeout)
223
224 def install_opener(opener):
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in open(self, fullurl, data, timeout)
523 req = meth(req)
524
--> 525 response = self._open(req, data)
526
527 # post-process response
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in _open(self, req, data)
541 protocol = req.type
542 result = self._call_chain(self.handle_open, protocol, protocol +
--> 543 '_open', req)
544 if result:
545 return result
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in _call_chain(self, chain, kind, meth_name, *args)
501 for handler in handlers:
502 func = getattr(handler, meth_name)
--> 503 result = func(*args)
504 if result is not None:
505 return result
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in https_open(self, req)
1358 def https_open(self, req):
1359 return self.do_open(http.client.HTTPSConnection, req,
-> 1360 context=self._context, check_hostname=self._check_hostname)
1361
1362 https_request = AbstractHTTPHandler.do_request_
/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py in do_open(self, http_class, req, **http_conn_args)
1317 encode_chunked=req.has_header('Transfer-encoding'))
1318 except OSError as err: # timeout error
-> 1319 raise URLError(err)
1320 r = h.getresponse()
1321 except:
URLError: <urlopen error [Errno 60] Operation timed out>
我对此错误感到很困惑，因此我看到该问题与URL有关，但我无法解决。在此之前，我通过pip安装了此模型：
pip3 install efficientnet_pytorch
如何解决此错误？预先谢谢你