data_spider
/
topic_spider


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241
							import re
from html import unescape
from urllib.parse import urlencode, urljoin

from bs4 import BeautifulSoup
from lxml.etree import ParseError
from lxml.html import etree, HtmlElement, fromstring, tostring
from urllib3 import get_host

from common.log import logger
from crawler.defaults import (
    USELESS_TAG,
    USELESS_ATTR,
    TAGS_CAN_BE_REMOVE_IF_EMPTY,
    VALID_WORDS,
    VOID_WORDS
)


def err_details(worker):
    worker_exception = worker.exception()
    if worker_exception:
        logger.exception("Worker return exception: {}".format(worker_exception))
    return worker


def extract_host(url):
    """

    # >>> base_url = extract_host('http://192.168.3.207:8080/')
    """
    _s, _h, _p = get_host(url)
    return f"{_s}://{_h}/" if _p is None else f"{_s}://{_h}:{_p}/"


def split_domain(val: str):
    if re.match(r'\d+', val) is None:
        return re.split(r'[\\.:]', val)
    return [val]


def extract_domain(url):
    """

    # >>> base_url = extract_domain('http://192.168.3.207:8080/')
    """
    _, host, port = get_host(url)
    return f"{host}" if port is None else f"{host}:{port}"


def extract_page_title(source):
    node = ''
    try:
        element = html2element(source)
        node = element.xpath('/html/head/title/text()|//title/text()')
    except ParseError:
        pass
    if len(node) > 1:
        return "".join(";".join(node).split())
    return "".join("".join(node).split())


def is_url(url):
    """判断url格式畸形与否"""
    _regex = re.compile(
        r'^(?:http|ftp)s?://'  # http:// or https://
        r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
        r'localhost|'  # localhost...
        r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'  # ...or ip
        r'(?::\d+)?'  # optional port
        r'(?:/?|[/?]\S+)$', re.IGNORECASE)
    return re.match(_regex, url) is not None


def is_domain(domain):
    _regex = re.compile(
        r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
        r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'  # ...or ip
        r'(?::\d+)?', re.IGNORECASE)
    return re.match(_regex, domain) is not None


def label_split(val):
    # '~`!#$%^&*()_+-=|\';"＂:/.,?><~·！@#￥%……&*（）——+-=“：’；、。，？》{《}】【\n\]\[ '
    result = re.split(r'[- _,，\\.|－「」【】?？！!/、] *', val)
    result = [v for v in result if len(v) > 0]
    return result


def get_url(url: str, parameters: dict):
    """
    拼接url与所带参数

    :param url: 链接
    :param parameters: 参数
    :return: 拼接后的url
    """
    _data = '?' + urlencode(parameters)
    return urljoin(url, _data)


def clean_html(source: str):
    html_str = re.sub(r'<!--[\s\S]*?-->', '', source)
    html_str = re.sub(r'<html>|<html [^>]*>|</html>', '', html_str)
    html_str = re.sub(r'<head>[\s\S]*?</head>', '', html_str)
    html_str = re.sub(r'<script[^<>]*>[\s\S]*?</script>|</script>', '', html_str)
    html_str = re.sub(r'<style[^<>]*>[\s\S]*?</style>', '', html_str)
    html_str = re.sub(r'<link[^<>]*>[\s\S]*?', '', html_str)
    html_str = re.sub(r'<img[^>]*>', '', html_str)
    return html_str


def extract_text(source: str):
    soup = BeautifulSoup(source, "lxml")
    return soup.get_text()


def verify_text(val: str, length=50):
    """检查数字、字母、中文的个数"""
    if val is None:
        return False
    sub_pattern = ['<[^>]+>', '[^0-9a-zA-Z\u4e00-\u9fa5]+']
    for pattern in sub_pattern:
        val = re.sub(pattern, '', val)
    # 若文本长度小于指定文本长度（length），表示页面内容无详情内容
    if len(val) < length:
        '''无效文本'''
        return False
    '''有效文本'''
    return True


def element2html(element: HtmlElement) -> str:
    return unescape(tostring(element, encoding="utf-8").decode())


def html2element(source: str, base_url=None) -> HtmlElement:
    html_str = re.sub('\ufeff|\xa0|\u3000|\x00', '', source)
    html_str = re.sub('<!--[\s\S]*?-->', '', html_str)  # 清除注释
    html_str = re.sub(r'<style[^<>]*>[\s\S]*?</style>', '', html_str)  # 清除样式
    html_str = re.sub(r'<script[^<>]*>[\s\S]*?</script>', '', html_str)  # 清除js
    html_str = re.sub('</?br.*?>', '', html_str)
    html_str = re.sub(r'<\?xml.*?>', '', html_str)
    html_str = re.sub(r'<[!]DOCTYPE.*?>', '', html_str)
    return fromstring(html_str, base_url=base_url)


def iter_node(element: HtmlElement, depth=1):
    yield element, depth
    depth += 1
    for sub_element in element:
        if isinstance(sub_element, HtmlElement):
            yield from iter_node(sub_element, depth)
    # print('退出', depth)


def remove_node(node: HtmlElement):
    """
    this is a in-place operation, not necessary to return
    :param node:
    :return:
    """
    parent = node.getparent()
    if parent is not None:
        node.drop_tree()
        # parent.remove(node)


def drop_tag(node: HtmlElement):
    """
    only delete the tag, but merge its text to parent.
    :param node:
    :return:
    """
    parent = node.getparent()
    if parent is not None:
        node.drop_tag()


def is_empty_element(node: HtmlElement):
    return not node.getchildren() and not node.text


def normalize_node(element: HtmlElement):
    etree.strip_elements(element, *USELESS_TAG, with_tail=False)
    # 节点预处理，删除节点与更新节点的操作在同一循环发生时，更新节点的操作不会生效，原因：？
    # 空节点合并、噪声节点剔除
    for node, _ in iter_node(element):
        if node.tag.lower() in TAGS_CAN_BE_REMOVE_IF_EMPTY and is_empty_element(node):
            remove_node(node)

        if node.tag.lower() == 'p':
            etree.strip_tags(node, 'span')
            etree.strip_tags(node, 'strong')

        # if a div tag does not contain any sub node, it could be converted to p node.
        if node.tag.lower() == 'div' and not node.getchildren():
            node.tag = 'p'

        if node.tag.lower() == 'span' and not node.getchildren():
            node.tag = 'p'

        # remove empty p tag
        if node.tag.lower() == 'p' and not node.xpath('.//img'):
            if not (node.text and node.text.strip()):
                drop_tag(node)

        # Delete inline styles
        style = node.get('style')
        if style:
            del node.attrib['style']

        # Obsolete scroll property
        if node.tag.lower() == 'marquee':
            remove_node(node)

    # 删除包含干扰属性的节点（完全匹配）
    for node, _ in iter_node(element):
        attr = (node.get('id') or node.get('class'))
        if attr:
            if attr.lower() in USELESS_ATTR:
                remove_node(node)
                break


def pre_parse(element):
    normalize_node(element)
    return element


def check_text_by_words(val: str):
    for word in VOID_WORDS:
        search = re.search(word, val)
        if search is not None:
            return False

    for keyword in VALID_WORDS:
        search = re.search(keyword, val)
        if search is not None:
            return True
    return False