当我使用 RTFM 时,我无法理解如何使用手册中描述的技术指定分页搜索。这是我的代码:
def find_documents(query_string, limit, cursor):
try:
subject_desc = search.SortExpression(
expression='date',
direction=search.SortExpression.DESCENDING,
default_value=datetime.now().date())
# Sort up to 1000 matching results by subject in descending order
sort = search.SortOptions(expressions=[subject_desc], limit=1000)
# Set query options
options = search.QueryOptions(
limit=limit, # the number of results to return
cursor=cursor,
sort_options=sort,
#returned_fields=['author', 'subject', 'summary'],
#snippeted_fields=['content']
)
query = search.Query(query_string=query_string, options=options)
index = search.Index(name=_INDEX_NAME)
# Execute the query
return index.search(query)
except search.Error:
logging.exception('Search failed')
return None
class MainAdvIndexedPage(SearchBaseHandler):
"""Handles search requests for comments."""
def get(self):
"""Handles a get request with a query."""
regionname = 'Delhi'
region = Region.all().filter('name = ', regionname).get()
uri = urlparse(self.request.uri)
query = ''
if uri.query:
query = parse_qs(uri.query)
query = query['query'][0]
results = find_documents(query, 50, search.Cursor())
next_cursor = results.cursor
template_values = {
'results': results,'next_cursor':next_cursor,
'number_returned': len(results.results),
'url': url, 'user' : users.get_current_user(),
'url_linktext': url_linktext, 'region' : region, 'city' : '', 'request' : self.request, 'form' : SearchForm(), 'query' : query
}
self.render_template('indexed.html', template_values)
上面的代码可以工作并进行搜索,但它不会对结果进行分页。我想知道手册中的以下代码:
next_cursor = results.cursor
next_cursor_urlsafe = next_cursor.web_safe_string
# save next_cursor_urlsafe
...
# restore next_cursor_urlsafe
results = find_documents(query_string, 20,
search.Cursor(web_safe_string=next_cursor_urlsafe))
是next_cursor
用来做什么的?我该如何存钱,存钱的目的是什么?我如何首先获得光标?代码是否应该看起来像这样,使用 memcache 保存恢复游标?
class MainAdvIndexedPage(SearchBaseHandler):
"""Handles search requests for comments."""
def get(self):
"""Handles a get request with a query."""
regionname = 'Delhi'
region = Region.all().filter('name = ', regionname).get()
uri = urlparse(self.request.uri)
query = ''
if uri.query:
query = parse_qs(uri.query)
query = query['query'][0]
# restore next_cursor_urlsafe
next_cursor_urlsafe = memcache.get('results_cursor')
if last_cursor:
results = find_documents(query_string, 50,
search.Cursor(web_safe_string=next_cursor_urlsafe))
results = find_documents(query, 50, search.Cursor())
next_cursor = results.cursor
next_cursor_urlsafe = next_cursor.web_safe_string
# save next_cursor_urlsafe
memcache.set('results_cursor', results.cursor)
template_values = {
'results': results,'next_cursor':next_cursor,
'number_returned': len(results.results),
'url': url, 'user' : users.get_current_user(),
'url_linktext': url_linktext, 'region' : region, 'city' : '', 'request' : self.request, 'form' : SearchForm(), 'query' : query
}
self.render_template('indexed.html', template_values)
更新
从我从答案中看到的,我应该使用 HTTP GET 查询字符串来保存光标,但我仍然不知道具体如何。请告诉我怎么做。
更新 2
这是我的新尝试。
def get(self):
"""Handles a get request with a query."""
regionname = 'Delhi'
region = Region.all().filter('name = ', regionname).get()
cursor = self.request.get("cursor")
uri = urlparse(self.request.uri)
query = ''
if uri.query:
query = parse_qs(uri.query)
query = query['query'][0]
logging.info('search cursor: %s', search.Cursor())
if cursor:
results = find_documents(query, 50, cursor)
else:
results = find_documents(query, 50, search.Cursor())
next_cursor = None
if results and results.cursor:
next_cursor = results.cursor.web_safe_string
logging.info('next cursor: %s', str(next_cursor))
template_values = {
'results': results,'cursor':next_cursor,
'number_returned': len(results.results),
'user' : users.get_current_user(),
'region' : region, 'city' : '', 'request' : self.request, 'form' : SearchForm(), 'query' : query
}
我认为我已经理解了它应该如何与上述内容一起工作,并且它在第一次点击时输出一个光标,所以我可以知道如何首先获得光标。这已经足够清楚地记录在案了。但我收到此错误消息:cursor must be a Cursor, got unicode