Export csv file from scrapy (not via command line)

That's what Feed Exports are for: http://doc.scrapy.org/en/latest/topics/feed-exports.html

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 a “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.

Why not use an item pipeline?

WriteToCsv.py

   import csv
   from YOUR_PROJECT_NAME_HERE import settings

   def write_to_csv(item):
       writer = csv.writer(open(settings.csv_file_path, 'a'), lineterminator='\n')
       writer.writerow([item[key] for key in item.keys()])

   class WriteToCsv(object):
        def process_item(self, item, spider):
            write_to_csv(item)
            return item

settings.py

   ITEM_PIPELINES = { 'project.pipelines_path.WriteToCsv.WriteToCsv' : A_NUMBER_HIGHER_THAN_ALL_OTHER_PIPELINES}
   csv_file_path = PATH_TO_CSV

If you wanted items to be written to separate csv for separate spiders you could give your spider a CSV_PATH field. Then in your pipeline use your spiders field instead of path from setttigs.

This works I tested it in my project.

HTH

http://doc.scrapy.org/en/latest/topics/item-pipeline.html