dcard-spider 0.3.0

A spider for Dcard through its newest API.

dcard-spider
============

|Build Status| |Coverage Status| |PyPI| |Land Health|

Get posts and forums resourses through Dcard practical API on website.

*Originally this is a module of my another project dcard-lumberjack <https://github.com/leVirve/dcard-lumberjack>.*


Feature
-------
Embrace asynchronous tasks and multithreads. All works done in parallel or coroutine-like.
**Spider needs for speed.**

Install
------------
::

$ pip install dcard-spider

Dependencies
------------
* Python 2.7+, Python 3.4+

Example
-------
Download images from the posts in specific forum.

* Through command
.. code:: bash

dcard download --forum photography --number 100

* Through programmable API
.. code:: python

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 all(status) else '出了點錯下載不完全喔')

.. image:: https://raw.githubusercontent.com/leVirve/dcard-spider/master/docs/img/snapshot.png
:width: 600px


Usage
-----

Full Commands
~~~~~~~~~~~~
.. code:: bash

$ dcard -h

usage: dcard [-h] [-f FORUM] [-n NUMBER] [-b BEFORE] [-likes LIKES_THRESHOLD]
[-o OUTPUT] [-F] [-v] [-V]
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

Command line
~~~~~~~~~~~~
::

dcard download -f [forums name] -n [number of posts]

(options:)
-likes [likes threshold]
-b [specified a starting post ID]
-o [output download folder]
-v [display and logging more info during execution]
-F [flatten all subfolders]
-V [show version of dcard-spider]

Basic
~~~~~

- 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。

.. code:: python

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``

.. code:: python

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)

.. code:: python

# 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

.. code:: python

# 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

.. code:: python

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)。

.. code:: python


# 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。

.. code:: python

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

.. code:: python

articles.downloader.subfolder_pattern = '[{likeCount}推] {id}-{folder_name}'
articles.downloader.flatten = True


What's next
-----------
This will be a library project for dcard continously crawling spider. And also provides end-user friendly features.


Licence
-------

**MIT**


Inspirations
------------
`SLMT's <https://github.com/SLMT>`_
`dcard-crawler <https://github.com/SLMT/dcard-crawler>`_

`Aragorn's <https://github.com/Elessar116>`_ downloader funtional request


.. |PyPI| image:: https://img.shields.io/pypi/v/dcard-spider.svg?style=flat-square
:target: https://pypi.python.org/pypi/dcard-spider
.. |Build Status| image:: https://img.shields.io/travis/leVirve/dcard-spider/master.svg?style=flat-square
:target: https://travis-ci.org/leVirve/dcard-spider
.. |Coverage Status| image:: https://img.shields.io/coveralls/leVirve/dcard-spider/master.svg?style=flat-square
:target: https://coveralls.io/github/leVirve/dcard-spider
.. |Land Health| image:: https://landscape.io/github/leVirve/dcard-spider/master/landscape.svg?style=flat-square
:target: https://landscape.io/github/leVirve/dcard-spider/master
:alt: Code Health