Why does python fail when loading data set “.load_data()”

问题

here is my code

import tensorflow as tf
from tensorflow import keras
import numpy as np
import matplotlib.pyplot as plt

data = keras.datasets.fashion_mnist

(train_images, train_labels), (test_images, test_labels) = data.load_data()

and it is giving me this long scary error:

Downloading data from https://storage.googleapis.com/tensorflow/tf-keras-datasets/train-labels-idx1-ubyte.gz
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1317, in do_open
    encode_chunked=req.has_header('Transfer-encoding'))
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1229, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1275, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1224, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1016, in _send_output
    self.send(msg)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 956, in send
    self.connect()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1392, in connect
    server_hostname=server_hostname)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 412, in wrap_socket
    session=session
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 853, in _create
    self.do_handshake()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 1117, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1056)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/majdbishara/PycharmProjects/machine/venv/lib/python3.7/site-packages/tensorflow_core/python/keras/utils/data_utils.py", line 264, in get_file
    urlretrieve(origin, fpath, dl_progress)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 247, in urlretrieve
    with contextlib.closing(urlopen(url, data)) as fp:
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 222, in urlopen
    return opener.open(url, data, timeout)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 525, in open
    response = self._open(req, data)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 543, in _open
    '_open', req)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 503, in _call_chain
    result = func(*args)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1360, in https_open
    context=self._context, check_hostname=self._check_hostname)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1319, in do_open
    raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1056)>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/majdbishara/PycharmProjects/machine learning/aaa.py", line 9, in <module>
    (train_images, train_labels), (test_images, test_labels) = data.load_data()
  File "/Users/majdbishara/PycharmProjects/machine/venv/lib/python3.7/site-packages/tensorflow_core/python/keras/datasets/fashion_mnist.py", line 52, in load_data
    paths.append(get_file(fname, origin=base + fname, cache_subdir=dirname))
  File "/Users/majdbishara/PycharmProjects/machine/venv/lib/python3.7/site-packages/tensorflow_core/python/keras/utils/data_utils.py", line 268, in get_file
    raise Exception(error_msg.format(origin, e.errno, e.reason))
Exception: URL fetch failure on https://storage.googleapis.com/tensorflow/tf-keras-datasets/train-labels-idx1-ubyte.gz: None -- [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1056)

I am really new to this so am really lost...

回答1:

This may be because you don't have python certificates installed, which is a pretty common error on Macs. You should be able to solve it by going into wherever you have Python installed and install your certificates by double clicking on your "Install Certificates.command" file.

Check this link here: Mac OSX python ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)

来源：https://stackoverflow.com/questions/59832388/why-does-python-fail-when-loading-data-set-load-data