最近聽到一首很喜歡的歌,許薇的《我以為》,評論也很有趣,遂有想爬取該歌曲下的所有評論並用詞雲工具展示。
我們使用chrome開發者工具,發現歌曲的評論都隱藏在以 R_SO_4 開頭的 XHR 文件中
接下來思路就很明確,拿到該文件,解析該文件的 json 數據,拿到全部評論。
我們可以看到該文件有兩個用JS加密的參數 params 和 encSecKey ,關於這兩個加密參數,參考了知乎用戶的解答:https://www.zhihu.com/question/36081767 。
步驟:
1.導入必要的模塊:
from Crypto.Cipher import AES from wordcloud import WordCloud #需加入下面兩句話,不然會報錯:matplotlib: RuntimeError: Python is not installed as a framework
import matplotlib matplotlib.use('TkAgg') import matplotlib.pyplot as plt import base64 import requests import json import codecs import time import jieba
注:本人使用MacOS,在該環境下會報錯,加入:
import matplotlib
matplotlib.use('TkAgg')
2.寫入請求頭:
headers = { 'Host':'music.163.com', 'Origin':'https://music.163.com', 'Referer':'https://music.163.com/song?id=28793052', 'User-Agent':'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36' }
3.解析 params 和 encSecKey 這兩個參數:
# 第一個參數 # first_param = '{rid:"", offset:"0", total:"true", limit:"20", csrf_token:""}' # 第二個參數
second_param = "010001"
# 第三個參數
third_param = "00e0b509f6259df8642dbc35662901477df22677ec152b5ff68ace615bb7b725152b3ab17a876aea8a5aa76d2e417629ec4ee341f56135fccf695280104e0312ecbda92557c93870114af6c9d05c4f7f0c3685b7a46bee255932575cce10b424d813cfe4875d3e82047b97ddef52741d546b8e289dc6935b3ece0462db0a22b8e7"
# 第四個參數
forth_param = "0CoJUm6Qyw8W8jud"
# 獲取參數
def get_params(page): # page為傳入頁數
iv = "0102030405060708" first_key = forth_param second_key = 16 * 'F'
if(page == 1): # 如果為第一頁
first_param = '{rid:"", offset:"0", total:"true", limit:"20", csrf_token:""}' h_encText = AES_encrypt(first_param, first_key, iv) else: offset = str((page-1)*20) first_param = '{rid:"", offset:"%s", total:"%s", limit:"20", csrf_token:""}' %(offset,'false') h_encText = AES_encrypt(first_param, first_key, iv) h_encText = AES_encrypt(h_encText, second_key, iv) return h_encText # 獲取 encSecKey
def get_encSecKey(): encSecKey = "257348aecb5e556c066de214e531faadd1c55d814f9be95fd06d6bff9f4c7a41f831f6394d5a3fd2e3881736d94a02ca919d952872e7d0a50ebfa1769a7a62d512f5f1ca21aec60bc3819a9c3ffca5eca9a0dba6d6f7249b06f5965ecfff3695b54e1c28f3f624750ed39e7de08fc8493242e26dbc4484a01c76f739e135637c"
return encSecKey # 解密過程
def AES_encrypt(text, key, iv): pad = 16 - len(text) % 16 text = text + pad * chr(pad) encryptor = AES.new(key, AES.MODE_CBC, iv) encrypt_text = encryptor.encrypt(text) encrypt_text = base64.b64encode(encrypt_text) encrypt_text = str(encrypt_text, encoding="utf-8") #注意一定要加上這一句,沒有這一句則出現錯誤
return encrypt_text
4.獲取 json 數據並抓取評論:
# 獲得評論json數據
def get_json(url, params, encSecKey): data = { "params": params, "encSecKey": encSecKey } response = requests.post(url, headers=headers, data=data) return response.content # 抓取某一首歌的評論
def get_all_comments(url,page): all_comments_list = [] # 存放所有評論
for i in range(page): # 逐頁抓取
params = get_params(i+1) encSecKey = get_encSecKey() json_text = get_json(url,params,encSecKey) json_dict = json.loads(json_text) for item in json_dict['comments']: comment = item['content'] # 評論內容
comment_info = str(comment) all_comments_list.append(comment_info) print('第%d頁抓取完畢!' % (i+1)) #time.sleep(random.choice(range(1,3))) #爬取過快的話,設置休眠時間,跑慢點,減輕服務器負擔
return all_comments_list
5.使用結巴分詞過濾停用詞並用 wordcloud 生成詞雲:
#生成詞雲
def wordcloud(all_comments): # 對句子進行分詞,加載停用詞
# 打開和保存文件時記得加encoding='utf-8'編碼,不然會報錯。
def seg_sentence(sentence): sentence_seged = jieba.cut(sentence.strip(), cut_all=False) # 精確模式
stopwords = [line.strip() for line in open('stopwords.txt', 'r', encoding='utf-8').readlines()] # 這里加載停用詞的路徑
outstr = ''
for word in sentence_seged: if word not in stopwords: if word != '\t': outstr += word outstr += " "
return outstr for line in all_comments: line_seg = seg_sentence(line) # 這里的返回值是字符串
with open('outputs.txt', 'a', encoding='utf-8') as f: f.write(line_seg + '\n') data = open('outputs.txt', 'r', encoding='utf-8').read() my_wordcloud = WordCloud( background_color='white', #設置背景顏色
max_words=200, #設置最大實現的字數
font_path=r'SimHei.ttf', #設置字體格式,如不設置顯示不了中文
).generate(data) plt.figure() plt.imshow(my_wordcloud) plt.axis('off') plt.show() # 展示詞雲
注意編碼格式為 'utf-8' 。
6.定義主函數並設置函數出口:
def main(): start_time = time.time() # 開始時間
url = "https://music.163.com/weapi/v1/resource/comments/R_SO_4_28793052?csrf_token=" # 替換為你想下載的歌曲R_SO的鏈接
all_comments = get_all_comments(url, page=2000) # 需要爬取的頁面數
wordcloud(all_comments) end_time = time.time() # 結束時間
print('程序耗時%f秒.' % (end_time - start_time)) if __name__ == '__main__': main()
運行過程如下(個人爬取了《我以為》的前2000頁的評論):
生成詞雲:
完整代碼已上傳至 github:https://github.com/weixuqin/PythonProjects/tree/master/wangyiyun