我在这里尝试做的是从不断刷新信息的动态页面检索数据.我设置的方式是每60秒刷新一次.问题是,旧数据不会从页面中删除,因此当程序在刷新后浏览数据时,会出现重复.
注意:由于最初没有要刮刮的消息,程序在开始时就处于休眠状态.
我正在寻找一种方法或解决方案,以使用最后一条记录(在这种情况下为message [-1])作为搜索的起点,以防止重复.
感谢所有帮助!谢谢.
driver.get(URL)
while 1==1:
time.sleep(60)
chat_page = driver.page_source
chat_soup = BeautifulSoup(chat_page,'lxml')
messages = chat_soup.findAll('div', attrs={'class':'message first'})
for message in messages:
username = message.div.h2.span.strong.text
text = message.find('div', attrs={'class':'markup'}).get_text()
timestamp = message.find('span', attrs={'class':'timestamp'}).get_text()
today = str(datetime.date.today())
timestamp = timestamp.replace('Today', today)
usernames.append(username)
timestamps.append(timestamp)
texts.append(text)
print(timestamp, username," : ",text)
我创建了一个临时解决方案,可以在将每个记录输入到SQLite3数据库之前对其进行检查.该程序可以通过使用“ INSERT OR IGNORE”来工作.不幸的是,该程序一直在检查重复项,因为它无法过滤掉已被抓取的数据.以下是我的临时解决方案:
driver.get(URL)
while 1==1:
chat_page = driver.page_source
chat_soup = BeautifulSoup(chat_page,'lxml')
messages = chat_soup.findAll('div', attrs={'class':'message first'})
for message in reversed(messages):
username = message.div.h2.span.strong.text
usernames.append(username)
text = message.find('div', attrs={'class':'markup'}).get_text()
text = text.replace('"', '')
text = text.replace("'", "")
username = username.replace('"', '')
username = username.replace("'", "")
timestamp = message.find('span', attrs={'class':'timestamp'}).get_text()
today = str(datetime.date.today())
timestamp = timestamp.replace('Today', today)
isbot = message.find('span', attrs={'class':'bot-tag'})
if (isbot):
username = '(BOT) ' + username
sql = '''INSERT OR IGNORE INTO 'chats' ('timestamp', 'username', 'text') VALUES ("%s", "%s", "%s")''' % (timestamp, username, text)
conn.executescript(sql)
解决方法:
我发现使用set.difference的解决方案效果很好.
在我的问题中,一次存在一定数量的数据(比如说10).我们希望在没有旧值的情况下获得新值.
olddata = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
newdata = [5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
unique_data = set(newdata).difference(olddata)
=
{11, 12, 13, 14}
最终工作代码:
while 1==1:
chat_page = driver.page_source
chat_soup = BeautifulSoup(chat_page,'lxml')
messages = chat_soup.findAll('div', attrs={'class':'message first'})
messages_dedupe = set(messages).difference(oldlist)
for message in messages_dedupe:
username = message.div.h2.span.strong.text
text = message.find('div', attrs={'class':'markup'}).get_text()
timestamp = message.find('span', attrs={'class':'timestamp'}).get_text()
today = str(datetime.date.today())
timestamp = timestamp.replace('Today', today)
isbot = message.find('span', attrs={'class':'bot-tag'})
if (isbot):
username = '(BOT) ' + username
usernames.append(username)
timestamps.append(timestamp)
texts.append(text)
oldlist = messages
sqlvalues = (username, timestamp, text)
c.execute("INSERT OR IGNORE INTO db (username, timestamp, text) VALUES (?, ?, ?)", sqlvalues)
conn.commit()
print(timestamp, username,":",text)
time.sleep(20)