Adding fields to item in scrapy from list

I have a long list of fields to add to a scrapy item but can't figure out how to do it. Basically I am trying to get the output of

class myItem(scrapy.Item):
a = scrapy.field()
b = scrapy.field()


But I want to create it from a list like

['a','b']


I tried

fields = ['a','b']

def generateFields(fields):
item = myItem()
for field in fields:
field = scrapy.Field()
return item


But that didn't work. Thanks!

1 Answer
1

You can manage it by using python magic method __dict__ pretty much as:

__dict__

fields = ['a', 'b', 'c']
class MyItem(scrapy.Item):
def __init__(self):
for f in fields:
self.__dict__[f] = scrapy.field()

my_item = MyItem()


And so on...
Seems that my previous comment is valid for usual python classes, not for scrapy.Item class. Following code is working:

scrapy.Item

from scrapy import Item, Field

fields = ['a', 'b', 'c']

def generate_item(fields):
item = Item()
for f in fields:
item.fields[f] = Field()
return item

item_instance = generate_item(fields)
item_instance['a'] = 'some_value'
item_instance['b'] = 12
print(item_instance)


__init__

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