I am playing around with a prime number generator. At one point, I decided to include the previous results right into my python source as a better starting spot. I cut and pasted 65,731 characters into a single line. It took about 30-60 seconds of CPU for PyCharm to finish rendering. I am not sure if this is some sort of incremental processing, compiling, or analysis but it took a surprisingly long time. I thought the program had crashed. It also takes 5-10 seconds to scroll from left to right on that line and the IDE is complaining about a trailing semicolon on the line that is not there.
Cutting and pasting the really long line to another location in the same file was much faster (basically instant). Before I was cutting and pasting from Chrome, I am not sure if that would make a difference.