Running python in sudo should fix this.
Also make sure you aren't using using any commands, like gpio.output(), before doing gpio.setup. This will also return a permission error.
I recently wrote a little tutorial for this library running on Jetson TX2 over on the nvidia devtalk site: https://devtalk.nvidia.com/default/topic/1030443/using-gpio-on-nvidia-jetson-tx2/?offset=4#5330619

hi everyone

i found that when fmode is w+ will throw a error even run with sudo

PermissionError: [Errno 13] Permission denied: '/sys/class/gpio/export'

but change it to w can resolve this problem

Curious. I wonder if this is true in all cases, or if we should add a way to customise FMODE.

hi everyone

gpio/gpio/__init__.py

Line 19 in fd8e954

FMODE = 'w+' # w+ overwrites and truncates existing files

i found that when fmode is w+ will throw a error even run with sudo

PermissionError: [Errno 13] Permission denied: '/sys/class/gpio/export'

but change it to w can resolve this problem

same for me, running version 1.0.0.
Maybe add a way for controlling F mode per pin?

some of them only need to be output only.

thanks

sounds like a reasonable feature/setting to add when creating pins