我正在尝试使用python访问ECMWF数据库并下载一组简单的数据尽管我遵循了网站上非常简单的说明：https://software.ecmwf.int/wiki/display/CKB/How+to+download+ERA-Interim+data+from+the+ECMWF+data+archive
我犯了以下错误。
怎么解决？
您也可以在下面找到使用的示例代码
我在windows 8上使用python 3.6.5
================== RESTART: C:\Users\Giulio\Desktop\test.py ==================
2018-05-21 12:08:29 ECMWF API python library 1.5.0
2018-05-21 12:08:29 ECMWF API at https://api.ecmwf.int/v1
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Error contacting the WebAPI, retrying in 60 seconds ...
Could not contact the WebAPI after 10 tries, failing !
Traceback (most recent call last):
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 1318, in do_open
encode_chunked=req.has_header('Transfer-encoding'))
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 1239, in request
self._send_request(method, url, body, headers, encode_chunked)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 1285, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 1234, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 1026, in _send_output
self.send(msg)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 964, in send
self.connect()
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\http\client.py", line 1400, in connect
server_hostname=server_hostname)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\ssl.py", line 407, in wrap_socket
_context=self, _session=session)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\ssl.py", line 814, in __init__
self.do_handshake()
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\ssl.py", line 1068, in do_handshake
self._sslobj.do_handshake()
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\ssl.py", line 689, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\Giulio\Desktop\test.py", line 19, in <module>
"target": "test.nc"
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\site-packages\ecmwfapi\api.py", line 519, in retrieve
c = APIRequest(self.url, "datasets/%s" % (dataset,), self.email, self.key, self.trace, verbose=self.verbose)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\site-packages\ecmwfapi\api.py", line 391, in __init__
user = self.connection.call("%s/%s" % (self.url, "who-am-i"))
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\site-packages\ecmwfapi\api.py", line 172, in wrapped
raise last_error
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\site-packages\ecmwfapi\api.py", line 140, in wrapped
return func(self, *args, **kwargs)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\site-packages\ecmwfapi\api.py", line 273, in call
res = opener.open(req)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 526, in open
response = self._open(req, data)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 544, in _open
'_open', req)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 504, in _call_chain
result = func(*args)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 1361, in https_open
context=self._context, check_hostname=self._check_hostname)
File "C:\Users\Giulio\AppData\Local\Programs\Python\Python36\lib\urllib\request.py", line 1320, in do_open
raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)>
脚本示例：
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "ei",
"dataset": "interim",
"expver": "1",
"stream": "oper",
"type": "fc",
"levtype": "sfc",
"param": "167.128",
"date": "2017-08-01/to/2017-08-03",
"time": "00:00:00",
"step": "3",
"grid": "0.75/0.75",
"area":"75/-20/10/60",
"format":"netcdf",
"target": "test.nc"
})
最佳答案
我通过以下链接解决了这个问题：https://software.ecmwf.int/wiki/display/WEBAPI/Web-API+Troubleshooting#Web-APITroubleshooting-3.2.1.3WARNING:httplib2.URLErrorreceivedNone%3Curlopenerror[SSL:CERTIFICATE_VERIFY_FAILED]certificateverifyfailed
问题可能是Python版本中使用的SSL库没有在正确的证书路径中查找。
在我的情况下，必须更新ca证书
Quovadis根CA 2 G3是api.ecmwf.int的根CA，可以从https://www.quovadisglobal.com/QVRepository/DownloadRootsAndCRL.aspx下载并在本地安装。
对于Windows，可以通过以下步骤完成：
1.在windows菜单的搜索栏上键入mmc.exe
2.转到文件>添加/删除管理单元>选择证书>单击添加>单击确定
3.扩展证书-当前用户
4.右键单击受信任的根证书颁发机构>所有任务>导入
5.遵循步骤
或者
certutil -addstore -f "ROOT" new-root-certificate.crt
在命令提示符下