使用python|使用python scrapy爬取天气并导出csv文件使用pythonscrapy爬取天气并导出

爬取xxx天气
安装
创建scray爬虫项目
文件说明
开始爬虫
补充：scrapy导出csv时字段的一些问题

1.字段顺序问题：
2.输出csv有空行的问题

总结

爬取xxx天气爬取网址：https://tianqi.2345.com/today-60038.htm

安装

pip install scrapy

【使用python|使用python scrapy爬取天气并导出csv文件】我使用的版本是scrapy 2.5

创建scray爬虫项目在命令行如下输入命令

scrapy startproject name

name为项目名称
如，scrapy startproject spider_weather
之后再输入

scrapy genspider spider_name 域名

如，scrapy genspider changshu tianqi.2345.com

查看文件夹

- spider_weather
- spider
- __init__.py
- changshu.py
- __init__.py
- items.py
- middlewares.py
- pipelines.py
- settings.py
- scrapy.cfg

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文件说明

名称	作用
scrapy.cfg	项目的配置信息，主要为Scrapy命令行工具提供一个基础的配置信息。（真正爬虫相关的配置信息在settings.py文件中）
items.py	设置数据存储模板，用于结构化数据，如：Django的Model
pipelines	数据处理行为，如：一般结构化的数据持久化
settings.py	配置文件，如：递归的层数、并发数，延迟下载等
spiders	爬虫目录，如：创建文件，编写爬虫规则

开始爬虫 1.在spiders文件夹里面对自己创建的爬虫文件进行数据爬取、如在此案例中的spiders/changshu.py
代码演示如下

import scrapyclass ChangshuSpider(scrapy.Spider):name = 'changshu'allowed_domains = ['tianqi.2345.com']start_urls = ['https://tianqi.2345.com/today-60038.htm']def parse(self, response):# 日期、天气状态、温度、风级# 利用xpath解析数据、不会xpath的同学可以去稍微学习一下，语法简单dates = response.xpath('//a[@class="seven-day-item "]/em/text()').getall()states = response.xpath('//a[@class="seven-day-item "]/i/text()').getall()temps = response.xpath('//a[@class="seven-day-item "]/span[@class="tem-show"]/text()').getall()winds = response.xpath('//a[@class="seven-day-item "]/span[@class="wind-name"]/text()').getall()# 返回每条数据for date, state, temp, wind in zip(dates,states,temps,winds):yield {'date' : date,'state': state,'temp': temp,'wind': wind}

2.在settings.py文件中进行配置
修改UA

USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36'

修改机器爬虫配置

ROBOTSTXT_OBEY = False

整个文件如下：

# Scrapy settings for spider_weather project## For simplicity, this file contains only settings considered important or# commonly used. You can find more settings consulting the documentation:##https://docs.scrapy.org/en/latest/topics/settings.html#https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#https://docs.scrapy.org/en/latest/topics/spider-middleware.htmlBOT_NAME = 'spider_weather'SPIDER_MODULES = ['spider_weather.spiders']NEWSPIDER_MODULE = 'spider_weather.spiders'# Crawl responsibly by identifying yourself (and your website) on the user-agentUSER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36'# Obey robots.txt rulesROBOTSTXT_OBEY = False# Configure maximum concurrent requests performed by Scrapy (default: 16)#CONCURRENT_REQUESTS = 32# Configure a delay for requests for the same website (default: 0)# See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay# See also autothrottle settings and docs#DOWNLOAD_DELAY = 3# The download delay setting will honor only one of:#CONCURRENT_REQUESTS_PER_DOMAIN = 16#CONCURRENT_REQUESTS_PER_IP = 16# Disable cookies (enabled by default)#COOKIES_ENABLED = False# Disable Telnet Console (enabled by default)#TELNETCONSOLE_ENABLED = False# Override the default request headers:#DEFAULT_REQUEST_HEADERS = {#'Accept': 'text/html,application/xhtml+xml,application/xml; q=0.9,*/*; q=0.8',#'Accept-Language': 'en',#}# Enable or disable spider middlewares# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html#SPIDER_MIDDLEWARES = {#'spider_weather.middlewares.SpiderWeatherSpiderMiddleware': 543,#}# Enable or disable downloader middlewares# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#DOWNLOADER_MIDDLEWARES = {#'spider_weather.middlewares.SpiderWeatherDownloaderMiddleware': 543,#}# Enable or disable extensions# See https://docs.scrapy.org/en/latest/topics/extensions.html#EXTENSIONS = {#'scrapy.extensions.telnet.TelnetConsole': None,#}# Configure item pipelines# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html# ITEM_PIPELINES = {#'spider_weather.pipelines.SpiderWeatherPipeline': 300,# }# Enable and configure the AutoThrottle extension (disabled by default)# See https://docs.scrapy.org/en/latest/topics/autothrottle.html#AUTOTHROTTLE_ENABLED = True# The initial download delay#AUTOTHROTTLE_START_DELAY = 5# The maximum download delay to be set in case of high latencies#AUTOTHROTTLE_MAX_DELAY = 60# The average number of requests Scrapy should be sending in parallel to# each remote server#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0# Enable showing throttling stats for every response received:#AUTOTHROTTLE_DEBUG = False# Enable and configure HTTP caching (disabled by default)# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings#HTTPCACHE_ENABLED = True#HTTPCACHE_EXPIRATION_SECS = 0#HTTPCACHE_DIR = 'httpcache'#HTTPCACHE_IGNORE_HTTP_CODES = []#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

3.然后在命令行中输入如下代码

scrapy crawl changshu -o weather.csv

注意：需要进入spider_weather路径下运行
scrapy crawl 文件名 -o weather.csv（导出文件）

4.结果如下

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补充：scrapy导出csv时字段的一些问题 scrapy -o csv格式输出的时候，发现输出文件中字段的顺序不是按照items.py中的顺序，也不是爬虫文件中写入的顺序，这样导出的数据因为某些字段变得不好看，此外，导出得csv文件不同的item之间被空行隔开，本文主要描述解决这些问题的方法。

1.字段顺序问题：
需要在scrapy的spiders同层目录，新建csv_item_exporter.py文件内容如下（文件名可改，目录定死）

from scrapy.conf import settingsfrom scrapy.contrib.exporter import CsvItemExporterclass MyProjectCsvItemExporter(CsvItemExporter):def init(self, *args, **kwargs):delimiter = settings.get(‘CSV_DELIMITER', ‘,')kwargs[‘delimiter'] = delimiterfields_to_export = settings.get(‘FIELDS_TO_EXPORT', [])if fields_to_export :kwargs[‘fields_to_export'] = fields_to_exportsuper(MyProjectCsvItemExporter, self).init(*args, **kwargs)

2)在settings.py中新增以下内容

#定义输出格式FEED_EXPORTERS = {‘csv': ‘project_name.spiders.csv_item_exporter.MyProjectCsvItemExporter',}#指定csv输出字段的顺序FIELDS_TO_EXPORT = [‘name',‘title',‘info']#指定分隔符CSV_DELIMITER = ‘,'

设定完毕，执行scrapy crawl spider -o spider.csv的时候，字段就按顺序来了

2.输出csv有空行的问题
此时你可能会发现csv文件中有空行，这是因为scrapy默认输出时，每个item之间的分隔符是空行
解决办法：
在找到exporters.py的CsvItemExporter类，大概在215行中增加newline="",即可。
也可以继承重写CsvItemExporter类

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