[英]Scraping multiple pages into list with beautifulsoup
我在Python中使用beautifulsoup4編寫了一個刮板程序,該程序對多頁加密貨幣值進行迭代,並返回開始值,最高值和結束值。 問題的抓取部分工作正常,但無法將其保存到我的列表中,只有最后一個添加到了列表中。
誰能幫我解決所有的問題? 我已經進行了數小時的搜索,但似乎找不到相關的答案。 代碼如下:
no_space = name_15.str.replace('\s+', '-')
#lists out the pages to scrape
for n in no_space:
page = 'https://coinmarketcap.com/currencies/' + n + '/historical-data/'
http = lib.PoolManager()
response = http.request('GET', page)
soup = BeautifulSoup(response.data, "lxml")
main_table = soup.find('tbody')
date=[]
open_p=[]
high_p=[]
low_p=[]
close_p=[]
table = []
for row in main_table.find_all('td'):
table_pull = row.find_all_previous('td') #other find methods aren't returning what I need, but this works just fine
table = [p.text.strip() for p in table_pull]
date = table[208:1:-7]
open_p = table[207:1:-7]
high_p = table[206:1:-7]
low_p = table[205:1:-7]
close_p = table[204:0:-7]
df=pd.DataFrame(date,columns=['Date'])
df['Open']=list(map(float,open_p))
df['High']=list(map(float,high_p))
df['Low']=list(map(float,low_p))
df['Close']=list(map(float,close_p))
print(df)
簡而言之,看起來您正在訪問所有“ td”元素,然后嘗試訪問該列表的先前元素,這是不必要的。 另外,正如@hoefling指出的那樣,您不斷在循環內覆蓋變量,這就是為什么您只返回列表中的最后一個元素的原因(換句話說,只有循環的最后一次迭代才設置值)該變量的所有先前變量均被覆蓋)。 抱歉,由於我的計算機上有防火牆,我目前無法對此進行測試。 請嘗試以下操作:
no_space = name_15.str.replace('\s+', '-')
#lists out the pages to scrape
for n in no_space:
page = 'https://coinmarketcap.com/currencies/' + n + '/historical-data/'
http = lib.PoolManager()
response = http.request('GET', page)
soup = BeautifulSoup(response.data, "lxml")
main_table = soup.find('tbody')
table = [p.text.strip() for p in main_table.find_all('td')]
#You will need to re-think these indices here to get the info you want
date = table[208:1:-7]
open_p = table[207:1:-7]
high_p = table[206:1:-7]
low_p = table[205:1:-7]
close_p = table[204:0:-7]
df=pd.DataFrame(date,columns=['Date'])
df['Open']=list(map(float,open_p))
df['High']=list(map(float,high_p))
df['Low']=list(map(float,low_p))
df['Close']=list(map(float,close_p))
print(df)
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