tinyCrawl Documentation¶
tinyCrawl 是一个微型轻量的爬虫框架,具有以下特点:
简单轻巧,没有任何第三方包的依赖
checkpoint断点续爬
支持多线程爬取
内置日志功能
使用简单
How to use 如何使用¶
tinyCrawl 支持2种运行方法
函数式:定义爬虫的方法 task(),实例化
BaseCrawl(iter_url, iter_num_range, thread_num)
后,调用其run
方法,以task对象
作为参数执行继承式:继承
BaseCrawl(iter_url, iter_num_range, thread_num)
,重写crawl()
和sink()
方法,其中crawl()
类似于上一方法中的爬虫方法task(),定义爬取单页的爬虫代码,sink()
是将结果输出的方法,最后执行main()
方法执行总程序
函数式¶
from tinyCrawl import BaseCrawl, RowContainer
from urllib.request import urlopen
from lxml import etree
# 定义xpath
song_name_xpath = '//div[@class="song-name"]/a/text()'
singer_xpath = '//div[@class="singers"]/a[1]/text()'
album_xpath = '//div[@class="album"]/a[1]/text()'
def task(url):
"""
定义爬取单页的爬虫代码
"""
# 定义数据存放的容器,容器名字就是最后爬取结果存放字典的self.out的key
song_name_list = RowContainer("song name")
singer_list = RowContainer("singer")
album_list = RowContainer("album")
page = urlopen(url).read().decode("utf-8", 'ignore')
parse = etree.HTML(page)
for _song_name, _singer, _album in zip(parse.xpath(song_name_xpath),
parse.xpath(singer_xpath),
parse.xpath(album_xpath)):
# 将数据append进指定容器中
song_name_list.append(str(_song_name))
singer_list.append(str(_singer))
album_list.append(str(_album))
if __name__ == '__main__':
# 第一个参数是链接地址,需通过 %s 定义页数等迭代的参数
# 第二个参数是迭代的范围,
# 第三个参数是启用的线程数,大于1就是多线程,等于1就是单线程
bc = BaseCrawl("http://example.com/?page=%s", range(1, 5), 3)
# 输入task的对象,开始执行程序
bc.run(task)
# 执行完毕后,通过out属性,获取结果
print(bc.out)
继承式¶
from tinyCrawl import BaseCrawl, RowContainer
from urllib.request import urlopen
from lxml import etree
import pandas as pd
# 需继承BaseCrawl类,覆写crawl和sink方法
class Scratch(BaseCrawl):
def __init__(self, iter_url, iter_num_range, thread_num):
super().__init__(iter_url, iter_num_range, thread_num)
# 覆写crawl方法
def crawl(self, url):
# 定义数据存放的容器,容器名字就是最后爬取结果存放字典的self.out的key
song_name_list = RowContainer("song name")
singer_list = RowContainer("singer")
album_list = RowContainer("album")
page = urlopen(url).read().decode("utf-8", 'ignore')
parse = etree.HTML(page)
for _song_name, _singer, _album in zip(parse.xpath(song_name_xpath),
parse.xpath(singer_xpath),
parse.xpath(album_xpath)):
# 将数据append进指定容器中
song_name_list.append(str(_song_name))
singer_list.append(str(_singer))
album_list.append(str(_album))
# 覆写sink方法,将爬取的结果输出
def sink(self):
# self.out是字典结构的结果,可以直接输入pandas存为dataframe
recent_music = pd.DataFrame(self.out)
recent_music.to_csv("D:/tmptest.csv", index=0)
if __name__ == '__main__':
mc = Scratch("http://example.com/?page=%s", range(1, 5), 3)
# 调用main函数执行程序
mc.main()
output:
2021-01-10 16:18:36,944 - base.py - __init__ - [line:30] - INFO: Checkpoint path: D:\breakpoint_page.txt
2021-01-10 16:18:38,539 - base.py - __source - [line:119] - INFO: Now is running on multithread mode, total thread num is `3`
2021-01-10 16:18:38,539 - base.py - __source - [line:126] - INFO: Total iteration num: 4
2021-01-10 16:18:38,541 - base.py - _multi_thread_wrap - [line:59] - INFO: ThreadPoolExecutor-1_0 now is processing: http://example.com/?page=1
2021-01-10 16:18:38,541 - base.py - _multi_thread_wrap - [line:59] - INFO: ThreadPoolExecutor-1_1 now is processing: http://example.com/?page=2
2021-01-10 16:18:38,542 - base.py - _multi_thread_wrap - [line:59] - INFO: ThreadPoolExecutor-1_2 now is processing: http://example.com/?page=3
2021-01-10 16:18:41,544 - base.py - __task_done - [line:115] - INFO: ThreadPoolExecutor-1_1 task finished; (Time took: 3.0009s)
2021-01-10 16:18:41,544 - base.py - __task_done - [line:115] - INFO: ThreadPoolExecutor-1_0 task finished; (Time took: 3.0019s)
2021-01-10 16:18:41,544 - base.py - __task_done - [line:115] - INFO: ThreadPoolExecutor-1_2 task finished; (Time took: 3.0009s)
2021-01-10 16:18:41,545 - base.py - _multi_thread_wrap - [line:59] - INFO: ThreadPoolExecutor-1_1 now is processing: http://example.com/?page=4
2021-01-10 16:18:44,551 - base.py - __task_done - [line:115] - INFO: ThreadPoolExecutor-1_1 task finished; (Time took: 3.0022s)
2021-01-10 16:18:44,551 - base.py - __source - [line:151] - INFO: All done. (Time took: 6.0102s)
Main parameters主要参数说明¶
iter_url 可传递参数的链接¶
BaseCrawl
类中的 iter_url
参数,是一个带格式化输出的链接:
iter_url = "http://example.com/?page=%s"
其中 %s
是python中的格式化输出的方法,使用过程中,将需遍历的参数(多为页数)置为 %s
,以让程序内部进行参数的迭代
iter_num_range 迭代参数¶
BaseCrawl
类中的 iter_num_range
参数,是一个可迭代的的对象,即含 __iter__
属性的对象::
例如range,list等迭代器
iter_num_range = range(1, 6, 1)
或者:
iter_num_range = [1, 2, 3, 4, 5]
即迭代的参数是从1到5的连续数列,通常是指爬取的页数,需要爬取从1到5页的内容。
Configurable parameters 可配置参数说明¶
以下参数可通过 Config
类的 set
方法进行设置:
checkpoint_dir_path
: checkpoint存放位置is_save_log
: 是否保存日志log_path
: 日志保存路径
from tinyCrawl import Config
# 实例化配置对象
config = Config()
# is_save_log默认不保存日志,即is_save_log为False,这里设置成True,即`保存日志`
config.set("is_save_log", True)
# 设置日志保存路径
config.set("log_path", "D:/log")