scrapy命令行

创建scrapy项目

(主要在命令行操作)
scrapy startproject 项目名
例：

C:\Users\董贺贺>scrapy startproject hongyanhuoshui
New Scrapy project 'hongyanhuoshui', using template directory 'D:\anaconda\lib\site-packages\scrapy\templates\project', created in:
    C:\Users\董贺贺\hongyanhuoshui

You can start your first spider with:
    cd hongyanhuoshui
    scrapy genspider example example.com

C:\Users\董贺贺>

这时候crawl的结构目录已经基本生成：

C:\Users\董贺贺>cd hongyanhuoshui

C:\Users\董贺贺\hongyanhuoshui>tree /f
卷 Windows-SSD 的文件夹 PATH 列表
卷序列号为 0026-9AA2
C:.
│  scrapy.cfg
│
└─hongyanhuoshui
    │  items.py
    │  middlewares.py
    │  pipelines.py
    │  settings.py
    │  __init__.py
    │
    ├─spiders
    │  │  __init__.py
    │  │
    │  └─__pycache__
    └─__pycache__

C:\Users\董贺贺\hongyanhuoshui>

根据第一段代码的提示，我们还可以创建spider.py文件，故我们创建了spider文件，并命名为hongyan.py，然后我们查看创建spider后的结构：

C:\Users\董贺贺\hongyanhuoshui> scrapy genspider hongyan https://www.baidu.com
Created spider 'hongyan' using template 'basic' in module:
  hongyanhuoshui.spiders.hongyan

C:\Users\董贺贺\hongyanhuoshui>tree /f
卷 Windows-SSD 的文件夹 PATH 列表
卷序列号为 0026-9AA2
C:.
│  scrapy.cfg
│
└─hongyanhuoshui
    │  items.py
    │  middlewares.py
    │  pipelines.py
    │  settings.py
    │  __init__.py
    │
    ├─spiders
    │  │  hongyan.py
    │  │  __init__.py
    │  │
    │  └─__pycache__
    │          __init__.cpython-37.pyc
    │
    └─__pycache__
            settings.cpython-37.pyc
            __init__.cpython-37.pyc


C:\Users\董贺贺\hongyanhuoshui>

对比上一段代码，显然spiders文件中多了hongyan.py，此文件对于我们执行爬虫文件必不可少。

关于命令行的详细使用

命令的使用范围

这里的命令分为全局的命令和项目的命令，全局的命令表示可以在任何地方使用，而项目的命令只能在项目目录下使用

可用的工具命令

C:\Users\董贺贺\hongyanhuoshui>scrapy -h
Scrapy 1.6.0 - project: hongyanhuoshui

Usage:
  scrapy <command> [options] [args]

Available commands:
  bench         Run quick benchmark test
  check         Check spider contracts
  crawl         Run a spider
  edit          Edit spider
  fetch         Fetch a URL using the Scrapy downloader
  genspider     Generate new spider using pre-defined templates
  list          List available spiders
  parse         Parse URL (using its spider) and print the results
  runspider     Run a self-contained spider (without creating a project)
  settings      Get settings values
  shell         Interactive scraping console
  startproject  Create new project
  version       Print Scrapy version
  view          Open URL in browser, as seen by Scrapy

Use "scrapy <command> -h" to see more info about a command

还可以通过crapy <command> -h，查看命令详情：

全局命令有：

• startproject
• genspider
• settings
• runspider
• shell
• fetch
• view
• version

项目命令有：

• crawl
• check
• list
• edit
• parse
• bench

---

startproject

这个东西没啥好说的，就是创建项目。scrapy startproject 项目名

genspider

用于生成爬虫，这里scrapy提供给我们不同的几种模板生成spider,默认用的是basic,我们可以通过命令查看所有的模板，默认情况下是先进入项目，即：

cd 项目名
scrapy genspider 文件名 目标网站

如果我们想更改默认怎么办，我么先看看主要有哪几种形式：

C:\Users\董贺贺\hongyanhuoshui>scrapy genspider -l
Available templates:
  basic
  crawl
  csvfeed
  xmlfeed

主要有四种形式，比如我们想使用crawl模式怎么更改呢(我重新完整的创建了新项目)：

C:\Users\董贺贺>scrapy startproject myproject
New Scrapy project 'myproject', using template directory 'D:\anaconda\lib\site-packages\scrapy\templates\project', created in:
    C:\Users\董贺贺\myproject

You can start your first spider with:
    cd myproject
    scrapy genspider example example.com

C:\Users\董贺贺>cd myproject

C:\Users\董贺贺\myproject>scrapy genspider -t crawl baidu https://www.baidu.com
Created spider 'baidu' using template 'crawl' in module:
  myproject.spiders.baidu

scrapy genspider -t 模板名 名称 网址

crawl

这个是用去启动spider爬虫格式为：
scrapy crawl 爬虫名字

C:\Users\董贺贺\myproject>scrapy crawl baidu
2019-07-17 15:02:17 [scrapy.utils.log] INFO: Scrapy 1.6.0 started (bot: myproject)
2019-07-17 15:02:17 [scrapy.utils.log] INFO: Versions: lxml 4.3.0.0, libxml2 2.9.8, cssselect 1.0.3, parsel 1.5.1, w3lib 1.20.0, Twisted 19.2.0, Python 3.7.0 (default, Jun 28 2018, 08:04:48) [MSC v.1912 64 bit (AMD64)], pyOpenSSL 18.0.0 (OpenSSL 1.1.1c  28 May 2019), cryptography 2.7, Platform Windows-10-10.0.17763-SP0
2019-07-17 15:02:17 [scrapy.crawler] INFO: Overridden settings: {'BOT_NAME': 'myproject', 'NEWSPIDER_MODULE': 'myproject.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MODULES': ['myproject.spiders']}
2019-07-17 15:02:17 [scrapy.extensions.telnet] INFO: Telnet Password: b57cecfc4210fb6c
2019-07-17 15:02:18 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.logstats.LogStats']
2019-07-17 15:02:18 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2019-07-17 15:02:18 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2019-07-17 15:02:18 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2019-07-17 15:02:18 [scrapy.core.engine] INFO: Spider opened
2019-07-17 15:02:18 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2019-07-17 15:02:18 [py.warnings] WARNING: D:\anaconda\lib\site-packages\scrapy\spidermiddlewares\offsite.py:61: URLWarning: allowed_domains accepts only domains, not URLs. Ignoring URL entry https://www.baidu.com in allowed_domains.
  warnings.warn(message, URLWarning)

2019-07-17 15:02:18 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6023
2019-07-17 15:02:20 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://https/robots.txt> (failed 1 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:22 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://https/robots.txt> (failed 2 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:25 [scrapy.downloadermiddlewares.retry] DEBUG: Gave up retrying <GET http://https/robots.txt> (failed 3 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:39 [scrapy.downloadermiddlewares.robotstxt] ERROR: Error downloading <GET http://https/robots.txt>: DNS lookup failed: no results for hostname lookup: https.
Traceback (most recent call last):
  File "D:\anaconda\lib\site-packages\twisted\internet\defer.py", line 1416, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "D:\anaconda\lib\site-packages\twisted\python\failure.py", line 512, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "D:\anaconda\lib\site-packages\scrapy\core\downloader\middleware.py", line 43, in process_request
    defer.returnValue((yield download_func(request=request,spider=spider)))
  File "D:\anaconda\lib\site-packages\twisted\internet\defer.py", line 654, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "D:\anaconda\lib\site-packages\twisted\internet\endpoints.py", line 975, in startConnectionAttempts
    "no results for hostname lookup: {}".format(self._hostStr)
twisted.internet.error.DNSLookupError: DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:41 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://https//www.baidu.com/> (failed 1 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:43 [scrapy.downloadermiddlewares.retry] DEBUG: Retrying <GET http://https//www.baidu.com/> (failed 2 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:45 [scrapy.downloadermiddlewares.retry] DEBUG: Gave up retrying <GET http://https//www.baidu.com/> (failed 3 times): DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:45 [scrapy.core.scraper] ERROR: Error downloading <GET http://https//www.baidu.com/>
Traceback (most recent call last):
  File "D:\anaconda\lib\site-packages\twisted\internet\defer.py", line 1416, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "D:\anaconda\lib\site-packages\twisted\python\failure.py", line 512, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "D:\anaconda\lib\site-packages\scrapy\core\downloader\middleware.py", line 43, in process_request
    defer.returnValue((yield download_func(request=request,spider=spider)))
  File "D:\anaconda\lib\site-packages\twisted\internet\defer.py", line 654, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "D:\anaconda\lib\site-packages\twisted\internet\endpoints.py", line 975, in startConnectionAttempts
    "no results for hostname lookup: {}".format(self._hostStr)
twisted.internet.error.DNSLookupError: DNS lookup failed: no results for hostname lookup: https.
2019-07-17 15:02:46 [scrapy.core.engine] INFO: Closing spider (finished)
2019-07-17 15:02:46 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/exception_count': 6,
 'downloader/exception_type_count/twisted.internet.error.DNSLookupError': 6,
 'downloader/request_bytes': 1299,
 'downloader/request_count': 6,
 'downloader/request_method_count/GET': 6,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2019, 7, 17, 7, 2, 46, 72694),
 'log_count/DEBUG': 6,
 'log_count/ERROR': 2,
 'log_count/INFO': 9,
 'log_count/WARNING': 1,
 'retry/count': 4,
 'retry/max_reached': 2,
 'retry/reason_count/twisted.internet.error.DNSLookupError': 4,
 "robotstxt/exception_count/<class 'twisted.internet.error.DNSLookupError'>": 1,
 'robotstxt/request_count': 1,
 'scheduler/dequeued': 3,
 'scheduler/dequeued/memory': 3,
 'scheduler/enqueued': 3,
 'scheduler/enqueued/memory': 3,
 'start_time': datetime.datetime(2019, 7, 17, 7, 2, 18, 354765)}
2019-07-17 15:02:46 [scrapy.core.engine] INFO: Spider closed (finished)

这里需要注意这里的爬虫名字和通过scrapy genspider 生成爬虫的名字是一致的

check

用于检查代码是否有错误，scrapy check

C:\Users\董贺贺\myproject>scrapy check

----------------------------------------------------------------------
Ran 0 contracts in 0.000s

OK

显然我们这段代码是没问题的

list

输出所有可用的爬虫文件

C:\Users\董贺贺\myproject>scrapy list
baidu

edit

edit 在命令行下编辑spider 不建议运行
scrapy edit myspider

fetch

scrapy fetch url地址
该命令会通过scrapy downloader 讲网页的源代码下载下来并显示出来
这里有一些参数：
--nolog 不打印日志
--headers 打印响应头信息
--no-redirect 不做跳转

# fetch 输出日志及网页源代码
scrapy fetch http://www.baidu.com

# fetch --nolog 只输出源代码
scrapy fetch --nolog http://www.baidu.com

# fetch --nolog --headers 输出响应头
scrapy fetch --nolog --headers http://www.baidu.com

# --nolog --no-redirect 禁止重定向
scrapy fetch --nolog --no-redirect http://www.baidu.com

scrapy

scrapy view url地址
该命令会讲网页document内容下载下来，并且在浏览器显示出来
例：scrapy view http://news.163.com

shell

这是一个命令行交互模式
通过scrapy shell url地址进入交互模式
这里我么可以通过css选择器以及xpath选择器获取我们想要的内容

C:\Users\董贺贺\myproject>scrapy shell www.baidu.com// --nolog
[s] Available Scrapy objects:
[s]   scrapy     scrapy module (contains scrapy.Request, scrapy.Selector, etc)
[s]   crawler    <scrapy.crawler.Crawler object at 0x0000013F362D2CC0>
[s]   item       {}
[s]   request    <GET http://www.baidu.com//>
[s]   settings   <scrapy.settings.Settings object at 0x0000013F362D2BE0>
[s] Useful shortcuts:
[s]   fetch(url[, redirect=True]) Fetch URL and update local objects (by default, redirects are followed)
[s]   fetch(req)                  Fetch a scrapy.Request and update local objects
[s]   shelp()           Shell help (print this help)
[s]   view(response)    View response in a browser
In [1]:

exit退出交互模式

settings

获取当前的配置信息
通过scrapy settings -h可以获取这个命令的所有帮助信息

C:\Users\董贺贺\myproject>scrapy settings -h
Usage
=====
  scrapy settings [options]

Get settings values

Options
=======
--help, -h              show this help message and exit
--get=SETTING           print raw setting value
--getbool=SETTING       print setting value, interpreted as a boolean
--getint=SETTING        print setting value, interpreted as an integer
--getfloat=SETTING      print setting value, interpreted as a float
--getlist=SETTING       print setting value, interpreted as a list

Global Options
--------------
--logfile=FILE          log file. if omitted stderr will be used
--loglevel=LEVEL, -L LEVEL
                        log level (default: DEBUG)
--nolog                 disable logging completely
--profile=FILE          write python cProfile stats to FILE
--pidfile=FILE          write process ID to FILE
--set=NAME=VALUE, -s NAME=VALUE
                        set/override setting (may be repeated)
--pdb                   enable pdb on failure

runspider

这个和通过crawl启动爬虫不同，这里是scrapy runspider 爬虫文件名称
所有的爬虫文件都是在项目目录下的spiders文件夹中

version

查看版本信息，并查看依赖库的信息

C:\Users\董贺贺\myproject>scrapy version
Scrapy 1.6.0

C:\Users\董贺贺\myproject>scrapy version -v
Scrapy       : 1.6.0
lxml         : 4.3.0.0
libxml2      : 2.9.8
cssselect    : 1.0.3
parsel       : 1.5.1
w3lib        : 1.20.0
Twisted      : 19.2.0
Python       : 3.7.0 (default, Jun 28 2018, 08:04:48) [MSC v.1912 64 bit (AMD64)]
pyOpenSSL    : 18.0.0 (OpenSSL 1.1.1c  28 May 2019)
cryptography : 2.7
Platform     : Windows-10-10.0.17763-SP0

shell是重点