scrapy-magicfields 1.1.0

Supported magic variables

$time

the UTC timestamp at which the item was scraped, in format '%Y-%m-%d %H:%M:%S'.

$unixtime

the unixtime (number of seconds since the Epoch, i.e. time.time()) at which the item was scraped.

$isotime

the UTC timestamp at which the item was scraped, with format '%Y-%m-%dT%H:%M:%S".

$spider

must be followed by an argument, which is the name of an attribute of the spider (like an argument passed to it).

$env

the value of an environment variable. It acccepts as argument the name of the variable.

$jobid

the job id (shortcut for $env:SCRAPY_JOB)

$jobtime

the UTC timestamp at which the job started, in format '%Y-%m-%d %H:%M:%S'.

$response

Access to some response properties.

$response:url

The url from where the item was extracted from.

$response:status

Response http status.

$response:headers

Response http headers.

$setting

Access the given Scrapy setting. It accepts one argument: the name of the setting.

$field

Allows to copy the value of one field to another Its argument is the source field. Effects are unpredicable if you use as source a field that is filled using magic fields.

Examples

The following configuration will add two fields to each scraped item:

• 'timestamp', which will be filled with the string 'item scraped at <scraped timestamp>',

• and 'spider', which will contain the spider name

MAGIC_FIELDS = {
    "timestamp": "item scraped at $time",
    "spider": "$spider:name"
}

The following configuration will copy the url to the field sku:

MAGIC_FIELDS = {
    "sku": "$field:url"
}

Magics also accept a regular expression argument which allows to extract and assign only part of the value generated by the magic. You have to specify it using the r'' notation.

Let’s pretend that the urls of your items look like 'http://www.example.com/product.html?item_no=345' and you want to assign to the sku field only the item number.

The following example, similar to the previous one but with a second regular expression argument, will do the task:

MAGIC_FIELDS = {
    "sku": "$field:url,r'item_no=(\d+)'"
}