Explicit message for scrapy parse callback
Explicit message for scrapy parse callback

The scrapy parse method raises a NotImplementedError when not defined,
but for new comers it can be hard to debug what might be going wrong.

Adding an explicit message for NotImplementedError will help new users.

ssteo/scrapy,eLRuLL/scrapy,pawelmhm/scrapy,ArturGaspar/scrapy,dangra/scrapy,pablohoffman/scrapy,elacuesta/scrapy,eLRuLL/scrapy,pawelmhm/scrapy,starrify/scrapy,Parlin-Galanodel/scrapy,finfish/scrapy,Parlin-Galanodel/scrapy,Ryezhang/scrapy,pablohoffman/scrapy,finfish/scrapy,wujuguang/scrapy,scrapy/scrapy,ArturGaspar/scrapy,umrashrf/scrapy,starrify/scrapy,dangra/scrapy,Ryezhang/scrapy,Parlin-Galanodel/scrapy,pablohoffman/scrapy,umrashrf/scrapy,Ryezhang/scrapy,finfish/scrapy,kmike/scrapy,elacuesta/scrapy,eLRuLL/scrapy,elacuesta/scrapy,pawelmhm/scrapy,wujuguang/scrapy,scrapy/scrapy,ssteo/scrapy,kmike/scrapy,ssteo/scrapy,kmike/scrapy,ArturGaspar/scrapy,starrify/scrapy,wujuguang/scrapy,umrashrf/scrapy,dangra/scrapy,scrapy/scrapy