我从 freebase 尝试了这个 python 示例并在我的 Windows 和 ubuntu 机器上运行它。
http://mql.freebaseapps.com/ch04.html
import sys # Command-line arguments, etc.
import simplejson # JSON encoding.
import urllib # URI encoding.
import urllib2 # High-level URL content fetching.
# These are some constants we'll use.
SERVER = 'api.freebase.com' # Metaweb server
SERVICE = '/api/service/mqlread' # Metaweb service
# Compose our MQL query as a Python data structure.
# The query is an array in case multiple bands share the same name.
band = sys.argv[1] # The desired band, from command line.
query = [{'type': '/music/artist', # Our MQL query in Python.
'name': band, # Place the band in the query.
'album': [{ 'name': None, # None is Python's null.
'release_date': None,
'sort': 'release_date' }]}]
# Put the query in an envelope
envelope = {
'query': query, # The query property specifies the query.
'escape': False # Turns off HTML escaping.
}
# These five lines are the key code for using mqlread
encoded = simplejson.dumps(envelope) # JSON encode the envelope.
params = urllib.urlencode({'query':encoded}) # Escape request parameters.
url ='http://%s%s?%s' % (SERVER,SERVICE,params) # The URL to request.
f = urllib2.urlopen(url) # Open the URL as a file.
response = simplejson.load(f) # Read and JSON parse response.
# Check for errors and exit with a message if the query failed.
if response['code'] != '/api/status/ok': # If not okay...
error = response['messages'][0] # First msg object.
sys.exit('%s: %s' % (error['code'], error['message'])) # Display code,msg.
# No errors, so handle the result
result = response['result'] # Open the response envelope, get result.
# Check the number of matching bands
if len(result) == 0:
sys.exit('Unknown band')
elif len(result) > 1:
print "Warning: multiple bands named " + band + ". Listing first only."
result = result[0] # Get first band from array of matches.
if not result['album']: # Exit if band has no albums
sys.exit(band + ' has no known albums.')
for album in result['album']: # Loop through the result albums.
name = album['name'] # Album name.
date = album['release_date'] # Release date timestamp or null.
if not date: date = ''
else: date = ' [%s]' % date[0:4] # Just the 4-digit year in brackets.
print "%s%s" % (name, date) # Print name and date.
但是，它没有用。有人可以解释为什么我得到这个错误吗？
Traceback (most recent call last):
File "mql.py", line 29, in <module>
f = urllib2.urlopen(url) # Open the URL as a file.
File "C:\Python27\lib\urllib2.py", line 126, in urlopen
return _opener.open(url, data, timeout)
File "C:\Python27\lib\urllib2.py", line 394, in open
response = self._open(req, data)
File "C:\Python27\lib\urllib2.py", line 412, in _open
'_open', req)
File "C:\Python27\lib\urllib2.py", line 372, in _call_chain
result = func(*args)
File "C:\Python27\lib\urllib2.py", line 1199, in http_open
return self.do_open(httplib.HTTPConnection, req)
File "C:\Python27\lib\urllib2.py", line 1168, in do_open
h.request(req.get_method(), req.get_selector(), req.data, headers)
File "C:\Python27\lib\httplib.py", line 955, in request
self._send_request(method, url, body, headers)
File "C:\Python27\lib\httplib.py", line 989, in _send_request
self.endheaders(body)
File "C:\Python27\lib\httplib.py", line 951, in endheaders
self._send_output(message_body)
File "C:\Python27\lib\httplib.py", line 811, in _send_output
self.send(msg)
File "C:\Python27\lib\httplib.py", line 773, in send
self.connect()
File "C:\Python27\lib\httplib.py", line 754, in connect
self.timeout, self.source_address)
File "C:\Python27\lib\socket.py", line 562, in create_connection
sock.connect(sa)
还有一件事，我使用的是 python 2.7，我没有任何特殊的互联网设置代理配置。