Dcard 爬蟲: dcard-spider
快如閃電的爬蟲，迅速獲得 Dcard 上所有看板的文章! Spider needs for speed.
Related to my side project dcard-lumberjack <https://github.com/leVirve/dcard-lumberjack>.
特色
- 一行指令下載看板內的所有文章及圖片
- 可程式化的 API 提供更靈活的操作
- 使用非同步 (asynchronous) 及 多執行序 (multithreading) 來平行完成併發任務達到最大校效率
安裝
$ pip install dcard-spider
必要需求
- Python 2.7+ or Python 3.4+
使用範例
下載指定看板中文章內的圖片
直接使用 command line
dcard download -f photography -n 100- 下載指令詳解
dcard download -f [forums 看板名稱] -n [數量]
(額外參數:)
-likes [likes 過濾門檻]
-b [指定起始文章 ID]
-o [輸出至...資料夾]
-F [平面化子資料夾 (各文章圖片在同一資料夾)]
透過程式 API
from dcard import Dcard
def 先過濾出標題含有作品關鍵字(metas):
return [meta for meta in metas if '#作品' in meta['title']]
if __name__ == '__main__':
dcard = Dcard()
metas = dcard.forums('photography').get_metas(num=100, callback=先過濾出標題含有作品關鍵字)
posts = dcard.posts(metas).get(comments=False, links=False)
resources = posts.parse_resources()
status, fails = posts.download(resources)
print('成功下載！' if len(fails) == 0 else '出了點錯下載不完全喔')詳細方法
Command-line 可用參數
$ dcard -h
usage: dcard [-h] [-f FORUM] [-n NUMBER] [-b BEFORE] [-likes LIKES_THRESHOLD]
[-o OUTPUT] [-F] [-v] [-V] [-c] [-l] [-p]
mode
positional arguments:
mode download / meta mode
optional arguments:
-h, --help show this help message and exit
-f FORUM, --forum FORUM Specific which forum
-n NUMBER, --number NUMBER Scan through how many posts
-b BEFORE, --before BEFORE Scan through before specified post ID
-likes LIKES_THRESHOLD, --likes_threshold LIKES_THRESHOLD
Specific minimum like counts
-o OUTPUT, --output OUTPUT Specific folder to store the resources
-F, --flatten Option for flattening folders
-v, --verbose Logging verbose information
-V, --version show program's version number and exit
-c, --comment Option for scrape comments
-l, --link Option for scrape links
-p, --popular Sort post by popularityBasic
- 取得看板資訊 (metadata)
- 可用參數
no_school調整是否取得學校看版內容。
- 可用參數
forums = dcard.forums.get()
forums = dcard.forums.get(no_school=True)- 取得看板文章資訊 (metadata)
- 可用
num指定文章數量 - 文章排序有兩種選擇:
new/popular
- 可用
ariticle_metas = dcard.forums('funny').get_metas(num=150, sort='new')
ariticle_metas = dcard.forums('funny').get_metas(num=100, sort='popular')
# get all the metas from forum
ariticle_metas = dcard.forums('funny').get_metas(num=Forum.infinite_page, sort='popular')- 提供一次取得多篇文章詳細資訊(全文、引用連結、所有留言)
# 可放入 文章編號/單一meta資訊 => return 單篇文章 in list
article = dcard.posts(224341009).get()
article = dcard.posts(ariticle_metas[0]).get()
# 放入 複數文章編號/多個meta資訊 => return 多篇文章 in list
ids = [meta['id'] for meta in ariticle_metas]
articles = dcard.posts(ids).get()
articles = dcard.posts(ariticle_metas).get()- 操作文章結果 PostsResult 物件
# 存取 articles 中的內容
# 1. articles.results -> get a `generator()`
for article in articles.results:
# `article` is a Python dict() object
# 2. articles.result() -> get a `list()`
for article in articles.result():
# `article` is a Python dict() object
# 3. Dumps all articles data into file directly
import json
with open('output.json', 'w', encoding='utf-8') as f:
json.dump(articles.result(), f, ensure_ascii=False)- 下載文章中的資源 (目前支援文中 imgur 連結的圖片)
- 預設每篇圖片儲存至
(#文章編號) 文章標題為名的新資料夾 .download()會回傳每個資源下載成功與否fails是一串下載失敗的 URL
- 預設每篇圖片儲存至
resources = articles.parse_resources()
status, fails = articles.download(resources)Advanced
- 提供自定義 callback function，可在接收回傳值前做處理 (filter / reduce data)。
# In `dcard.forums().get_metas()`
def collect_ids(metas):
return [meta['id'] for meta in metas]
def likes_count_greater(metas):
return [meta['id'] for meta in metas if meta['likeCount'] >= 20]
def 標題含有圖片關鍵字(metas):
return [meta['id'] for meta in metas if '#圖' in meta['title']]
ids = dcard.forums('funny').get_metas(num=50, callback=collect_ids)
ids = dcard.forums('funny').get_metas(num=50, callback=標題含有圖片關鍵字)
# In `dcard.posts().get()`, take `MongoDB` as backend database for example
def store_to_db(posts):
result = db[forum_name].insert_many([p for p in posts])
print('#Forum {}: insert {} items'.format(forum_name, len(result.inserted_ids)))
none_return_value = dcard.posts(metas).get(callback=store_to_db)- 爬取文章時提供 content, links, comments 三個參數，能選擇略過不需要的資訊以加快爬蟲速度。
posts = dcard.posts(ids).get(comments=False, links=False)- class
Posts下的downloader提供 hacking 選項subfolder_pattern可自定義子資料夾命名規則flatten選項可選擇將所有資源(圖片)放在一層資料夾下，而不要按照文章分子資料夾
articles.downloader.subfolder_pattern = '[{likeCount}推] {id}-{folder_name}'
articles.downloader.flatten = TrueWhat's next
This will be a library project for dcard continously crawling spider. And also provides end-user friendly features.
Licence
MIT
Inspirations
Aragorn's downloader funtional request