scrapy/docs/topics/commands.rst

.. _topics-commands:

=================
Command line tool
=================

.. versionadded:: 0.10

Scrapy is controlled through the ``scrapy`` command-line tool, to be referred
here as the "Scrapy tool" to differentiate it from their sub-commands which we
just call "commands", or "Scrapy commands".

The Scrapy tool provides several commands, for multiple purposes, and each one
accepts a different set of arguments and options.

.. _topics-project-structure:

Default structure of Scrapy projects
====================================

Before delving into the command-line tool and its sub-commands, let's first
understand the directory structure of a Scrapy project.

Even thought it can be modified, all Scrapy projects have the same file
structure by default, similar to this::

   scrapy.cfg
   myproject/
       __init__.py
       items.py
       pipelines.py
       settings.py
       spiders/
           __init__.py
           spider1.py
           spider2.py
           ...
   .scrapy/
       scrapy.db

The directory where the ``scrapy.cfg`` file resides is known as the *project
root directory*. That file contains the name of the python module that defines
the project settings. Here is an example::

    [settings]
    default = myproject.settings

By default, Scrapy projects use a SQLite_ database to store persistent runtime
data of the project, such as the spider queue (the list of spiders that are
scheduled to run).  By default, this SQLite database is stored in the *project
data directory* which, by default, is the ``.scrapy`` directory inside the
project root directory mentioned above.

Using the ``scrapy`` tool
=========================

You can start by running the Scrapy tool with no arguments and it will print
some usage help and the available commands::

    Scrapy X.Y - no active project

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

    Available commands:
      crawl         Start crawling a spider or URL
      fetch         Fetch a URL using the Scrapy downloader
    [...]

The first line will print the currently active project, if you're inside a
Scrapy project. In this, it was run from outside a project. If run from inside
a project it would have printed something like this::

    Scrapy X.Y - project: myproject

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

    [...]

Creating projects
-----------------

The first thing you typically do with the ``scrapy`` tool is create your Scrapy
project::

    scrapy startproject myproject

That will create a Scrapy project under the ``myproject`` directory.

Next, you go inside the new project directory::

    cd myproject

And you're ready to use use the ``scrapy`` command to manage and control your
project from there.

Controlling projects
--------------------

You use the ``scrapy`` tool from inside your projects to control and manage
them.

For example, to create a new spider::

    scrapy genspider mydomain mydomain.com

Some Scrapy commands (like :command:`crawl`) must be run from inside a Scrapy
project. See the :ref:`commands reference <topics-commands-ref>` below for more
information on which commands must be run from inside projects, and which not.

Also keep in mind that some commands may have slightly different behaviours
when running them from inside projects. For example, the fetch command will use
spider-overridden behaviours (such as custom :setting:`USER_AGENT` per-spider
setting) if the url being fetched is associated with some specific spider. This
is intentional, as the ``fetch`` command is meant to be used to check how
spiders are downloading pages.

.. _topics-commands-ref:

Available tool commands
=======================

This section contains a list of the available built-in commands with a
description and some usage examples. Remember you can always get more info
about each command by running::

    scrapy <command> -h

And you can see all available commands with::

    scrapy -h

There are two kinds of commands, those that only work from inside a Scrapy
project (Project-specific commands) and those that also work without an active
Scrapy project (Global commands), though they may behave slightly different
when running from inside a project (as they would use the project overriden
settings).

Global commands:

* :command:`startproject`
* :command:`settings`
* :command:`runspider`
* :command:`shell`
* :command:`fetch`
* :command:`view`
* :command:`version`

Project-only commands:

* :command:`crawl`
* :command:`list`
* :command:`parse`
* :command:`genspider`
* :command:`server`
* :command:`deploy`

.. command:: startproject

startproject
------------

* Syntax: ``scrapy startproject <project_name>``
* Requires project: *no*

Creates a new Scrapy project named ``project_name``, under the ``project_name``
directory.

Usage example::

    $ scrapy startproject myproject

.. command:: genspider

genspider
---------

* Syntax: ``scrapy genspider [-t template] <name> <domain>``
* Requires project: *yes*

Create a new spider in the current project.

This is just a convenient shortcut command for creating spiders based on
pre-defined templates, but certainly not the only way to create spiders. You
can just create the spider source code files yourself, instead of using this
command.

Usage example::

    $ scrapy genspider -l
    Available templates:
      basic
      crawl
      csvfeed
      xmlfeed

    $ scrapy genspider -d basic
    from scrapy.spider import BaseSpider

    class $classname(BaseSpider):
        name = "$name"
        allowed_domains = ["$domain"]
        start_urls = (
            'http://www.$domain/',
            )

        def parse(self, response):
            pass

    $ scrapy genspider -t basic example example.com
    Created spider 'example' using template 'basic' in module:
      mybot.spiders.example

.. command:: crawl

crawl
-----

* Syntax: ``scrapy crawl <spider|url>``
* Requires project: *yes*

Start crawling a spider. If a URL is passed instead of a spider, it will start
from that URL instead of the spider start urls.

Usage examples::

    $ scrapy crawl example.com
    [ ... example.com spider starts crawling ... ]

    $ scrapy crawl myspider
    [ ... myspider starts crawling ... ]

    $ scrapy crawl http://example.com/some/page.html
    [ ... spider that handles example.com starts crawling from that url ... ]

.. command:: server

server
------

* Syntax: ``scrapy server``
* Requires project: *yes*

Start Scrapyd server for this project, which can be referred from the JSON API
with the project name ``default``. For more info see: :ref:`topics-scrapyd`.

Usage example::

    $ scrapy server
    [ ... scrapyd starts and stays idle waiting for spiders to get scheduled ... ]

To schedule spiders, use the Scrapyd JSON API.

.. command:: list

list
----

* Syntax: ``scrapy list``
* Requires project: *yes*

List all available spiders in the current project. The output is one spider per
line.

Usage example::

    $ scrapy list
    spider1
    spider2

.. command:: fetch

fetch
-----

* Syntax: ``scrapy fetch <url>``
* Requires project: *no*

Downloads the given URL using the Scrapy downloader and writes the contents to
standard output.

The interesting thing about this command is that it fetches the page how the
the spider would download it. For example, if the spider has an ``USER_AGENT``
attribute which overrides the User Agent, it will use that one.

So this command can be used to "see" how your spider would fetch certain page.

If used outside a project, no particular per-spider behaviour would be applied
and it will just use the default Scrapy downloder settings.

Usage examples::

    $ scrapy fetch --nolog http://www.example.com/some/page.html
    [ ... html content here ... ]

    $ scrapy fetch --nolog --headers http://www.example.com/
    {'Accept-Ranges': ['bytes'],
     'Age': ['1263   '],
     'Connection': ['close     '],
     'Content-Length': ['596'],
     'Content-Type': ['text/html; charset=UTF-8'],
     'Date': ['Wed, 18 Aug 2010 23:59:46 GMT'],
     'Etag': ['"573c1-254-48c9c87349680"'],
     'Last-Modified': ['Fri, 30 Jul 2010 15:30:18 GMT'],
     'Server': ['Apache/2.2.3 (CentOS)']}

.. command:: view

view
----

* Syntax: ``scrapy view <url>``
* Requires project: *no*

Opens the given URL in a browser, as your Scrapy spider would "see" it.
Sometimes spiders see pages differently from regular users, so this can be used
to check what the spider "sees" and confirm it's what you expect.

Usage example::

    $ scrapy view http://www.example.com/some/page.html
    [ ... browser starts ... ]

.. command:: shell

shell
-----

* Syntax: ``scrapy shell [url]``
* Requires project: *no*

Starts the Scrapy shell for the given URL (if given) or empty if not URL is
given. See :ref:`topics-shell` for more info.

Usage example::

    $ scrapy shell http://www.example.com/some/page.html
    [ ... scrapy shell starts ... ]

.. command:: parse

parse
-----

* Syntax: ``scrapy parse <url> [options]``
* Requires project: *yes*

Fetches the given URL and parses with the spider that handles it, using the
method passed with the ``--callback`` option, or ``parse`` if not given.

Supported options:

* ``--callback`` or ``-c``: spider method to use as callback for parsing the
  response

* ``--rules`` or ``-r``: use :class:`~scrapy.contrib.spiders.CrawlSpider`
  rules to discover the callback (ie. spider method) to use for parsing the
  response

* ``--noitems``: don't show extracted links

* ``--nolinks``: don't show scraped items

Usage example::

    $ scrapy parse http://www.example.com/ -c parse_item
    [ ... scrapy log lines crawling example.com spider ... ]
    # Scraped Items - callback: parse ------------------------------------------------------------
    MyItem({'name': u"Example item",
     'category': u'Furniture',
     'length': u'12 cm'}
    )

.. command:: settings

settings
--------

* Syntax: ``scrapy settings [options]``
* Requires project: *no*

Get the value of a Scrapy setting.

If used inside a project it'll show the project setting value, otherwise it'll
show the default Scrapy value for that setting.

Example usage::

    $ scrapy settings --get BOT_NAME
    scrapybot
    $ scrapy settings --get DOWNLOAD_DELAY
    0

.. command:: runspider

runspider
---------

* Syntax: ``scrapy runspider <spider_file.py>``
* Requires project: *no*

Run a spider self-contained in a Python file, without having to create a
project.

Example usage::

    $ scrapy runspider myspider.py
    [ ... spider starts crawling ... ]

.. command:: version

version
-------

* Syntax: ``scrapy version [-v]``
* Requires project: *no*

Prints the Scrapy version. If used with ``-v`` it also prints Python, Twisted
and Platform info, which is useful for bug reports.

.. command:: deploy

deploy
------

.. versionadded:: 0.11

* Syntax: ``scrapy deploy [ <target:project> | -l <target> | -L ]``
* Requires project: *yes*

Deploy the project into a Scrapyd server. See :ref:`topics-deploying`.

Custom project commands
=======================

You can also add your custom project commands by using the
:setting:`COMMANDS_MODULE` setting. See the Scrapy commands in
`scrapy/commands`_ for examples on how to implement your commands.

.. _scrapy/commands: http://dev.scrapy.org/browser/scrapy/commands
.. setting:: COMMANDS_MODULE

COMMANDS_MODULE
---------------

Default: ``''`` (empty string)

A module to use for looking custom Scrapy commands. This is used to add custom
commands for your Scrapy project.

Example::

    COMMANDS_MODULE = 'mybot.commands'

.. _SQLite: http://en.wikipedia.org/wiki/SQLite