Add flag to disable Scraped debug messages

[krisztian-toth]

Summary

Add a flag to settings (e.g. LOG_SCRAPED_ENABLED) to be able to disable the logging of each scraped Item on DEBUG level.

Motivation

Crawling with Scrapy on log level DEBUG provides a lot of useful context during development. The only problem is the "scraped" message (constructed in scrapy.logformatter.LogFormatter.scraped) - it obfuscates the log entirely in the command line and can be really frustrating in general. Adding a flag to disable this log message (with a default value so that the current behaviour doesn't change) would be really useful.

Describe alternatives you've considered

Right now you either put up with it or use INFO level instead which makes you lose a lot of useful log entries available in DEBUG level.

[elacuesta]

Seems like a valid request, I have seen my logs flooded with those messages as well.
I believe it shouldn't be too hard to implement, probably just an if check around these lines.

[krisztian-toth]

Thanks @elacuesta, that's what I thought as well, I'd be happy to pick this up when I have a bit of time.