Feed exports¶
New in version 0.10.
One of the most frequently required features when implementing scrapers is being able to store the scraped data properly and, quite often, that means generating an “export file” with the scraped data (commonly called “export feed”) to be consumed by other systems.
Scrapy provides this functionality out of the box with the Feed Exports, which allows you to generate a feed with the scraped items, using multiple serialization formats and storage backends.
Serialization formats¶
For serializing the scraped data, the feed exports use the Item exporters. These formats are supported out of the box:
But you can also extend the supported format through the
FEED_EXPORTERS
setting.
JSON¶
FEED_FORMAT
:json
Exporter used:
JsonItemExporter
See this warning if you’re using JSON with large feeds.
JSON lines¶
FEED_FORMAT
:jsonlines
Exporter used:
JsonLinesItemExporter
CSV¶
FEED_FORMAT
:csv
Exporter used:
CsvItemExporter
To specify columns to export and their order use
FEED_EXPORT_FIELDS
. Other feed exporters can also use this option, but it is important for CSV because unlike many other export formats CSV uses a fixed header.
XML¶
FEED_FORMAT
:xml
Exporter used:
XmlItemExporter
Pickle¶
FEED_FORMAT
:pickle
Exporter used:
PickleItemExporter
Marshal¶
FEED_FORMAT
:marshal
Exporter used:
MarshalItemExporter
Storages¶
When using the feed exports you define where to store the feed using a URI
(through the FEED_URI
setting). The feed exports supports multiple
storage backend types which are defined by the URI scheme.
The storages backends supported out of the box are:
Some storage backends may be unavailable if the required external libraries are not available. For example, the S3 backend is only available if the botocore or boto library is installed (Scrapy supports boto only on Python 2).
Storage URI parameters¶
The storage URI can also contain parameters that get replaced when the feed is being created. These parameters are:
%(time)s
- gets replaced by a timestamp when the feed is being created
%(name)s
- gets replaced by the spider name
Any other named parameter gets replaced by the spider attribute of the same
name. For example, %(site_id)s
would get replaced by the spider.site_id
attribute the moment the feed is being created.
Here are some examples to illustrate:
Store in FTP using one directory per spider:
ftp://user:password@ftp.example.com/scraping/feeds/%(name)s/%(time)s.json
Store in S3 using one directory per spider:
s3://mybucket/scraping/feeds/%(name)s/%(time)s.json
Storage backends¶
Local filesystem¶
The feeds are stored in the local filesystem.
URI scheme:
file
Example URI:
file:///tmp/export.csv
Required external libraries: none
Note that for the local filesystem storage (only) you can omit the scheme if
you specify an absolute path like /tmp/export.csv
. This only works on Unix
systems though.
FTP¶
The feeds are stored in a FTP server.
URI scheme:
ftp
Example URI:
ftp://user:pass@ftp.example.com/path/to/export.csv
Required external libraries: none
FTP supports two different connection modes: active or passive. Scrapy uses the passive connection
mode by default. To use the active connection mode instead, set the
FEED_STORAGE_FTP_ACTIVE
setting to True
.
S3¶
The feeds are stored on Amazon S3.
The AWS credentials can be passed as user/password in the URI, or they can be passed through the following settings:
You can also define a custom ACL for exported feeds using this setting:
Standard output¶
The feeds are written to the standard output of the Scrapy process.
URI scheme:
stdout
Example URI:
stdout:
Required external libraries: none
Settings¶
These are the settings used for configuring the feed exports:
FEED_URI¶
Default: None
The URI of the export feed. See Storage backends for supported URI schemes.
This setting is required for enabling the feed exports.
FEED_FORMAT¶
The serialization format to be used for the feed. See Serialization formats for possible values.
FEED_EXPORT_ENCODING¶
Default: None
The encoding to be used for the feed.
If unset or set to None
(default) it uses UTF-8 for everything except JSON output,
which uses safe numeric encoding (\uXXXX
sequences) for historic reasons.
Use utf-8
if you want UTF-8 for JSON too.
FEED_EXPORT_FIELDS¶
Default: None
A list of fields to export, optional.
Example: FEED_EXPORT_FIELDS = ["foo", "bar", "baz"]
.
Use FEED_EXPORT_FIELDS option to define fields to export and their order.
When FEED_EXPORT_FIELDS is empty or None (default), Scrapy uses fields
defined in dicts or Item
subclasses a spider is yielding.
If an exporter requires a fixed set of fields (this is the case for CSV export format) and FEED_EXPORT_FIELDS is empty or None, then Scrapy tries to infer field names from the exported data - currently it uses field names from the first item.
FEED_EXPORT_INDENT¶
Default: 0
Amount of spaces used to indent the output on each level. If FEED_EXPORT_INDENT
is a non-negative integer, then array elements and object members will be pretty-printed
with that indent level. An indent level of 0
(the default), or negative,
will put each item on a new line. None
selects the most compact representation.
Currently implemented only by JsonItemExporter
and XmlItemExporter
, i.e. when you are exporting
to .json
or .xml
.
FEED_STORE_EMPTY¶
Default: False
Whether to export empty feeds (ie. feeds with no items).
FEED_STORAGES¶
Default: {}
A dict containing additional feed storage backends supported by your project. The keys are URI schemes and the values are paths to storage classes.
FEED_STORAGE_FTP_ACTIVE¶
Default: False
Whether to use the active connection mode when exporting feeds to an FTP server
(True
) or use the passive connection mode instead (False
, default).
For information about FTP connection modes, see What is the difference between active and passive FTP?.
FEED_STORAGE_S3_ACL¶
Default: ''
(empty string)
A string containing a custom ACL for feeds exported to Amazon S3 by your project.
For a complete list of available values, access the Canned ACL section on Amazon S3 docs.
FEED_STORAGES_BASE¶
Default:
{
'': 'scrapy.extensions.feedexport.FileFeedStorage',
'file': 'scrapy.extensions.feedexport.FileFeedStorage',
'stdout': 'scrapy.extensions.feedexport.StdoutFeedStorage',
's3': 'scrapy.extensions.feedexport.S3FeedStorage',
'ftp': 'scrapy.extensions.feedexport.FTPFeedStorage',
}
A dict containing the built-in feed storage backends supported by Scrapy. You
can disable any of these backends by assigning None
to their URI scheme in
FEED_STORAGES
. E.g., to disable the built-in FTP storage backend
(without replacement), place this in your settings.py
:
FEED_STORAGES = {
'ftp': None,
}
FEED_EXPORTERS¶
Default: {}
A dict containing additional exporters supported by your project. The keys are serialization formats and the values are paths to Item exporter classes.
FEED_EXPORTERS_BASE¶
Default:
{
'json': 'scrapy.exporters.JsonItemExporter',
'jsonlines': 'scrapy.exporters.JsonLinesItemExporter',
'jl': 'scrapy.exporters.JsonLinesItemExporter',
'csv': 'scrapy.exporters.CsvItemExporter',
'xml': 'scrapy.exporters.XmlItemExporter',
'marshal': 'scrapy.exporters.MarshalItemExporter',
'pickle': 'scrapy.exporters.PickleItemExporter',
}
A dict containing the built-in feed exporters supported by Scrapy. You can
disable any of these exporters by assigning None
to their serialization
format in FEED_EXPORTERS
. E.g., to disable the built-in CSV exporter
(without replacement), place this in your settings.py
:
FEED_EXPORTERS = {
'csv': None,
}