[curious_dg]

if i am using using python for web development,GUI apps,etc and need good documentation and support then i choose pyCharm
But your requirement is fast and lightweight then you can choose from below if you like..

If i am using in in rasperberry pi or any other VMs/VPS which have low space then i would like to go for
>>IDLE,
>>VIM(with plugin),
>>Spyder
>>Emacs(python-mode)
>>jupyter notebook

For machine learning and AI based projects where auto-completion and project management easily can be done by
Emacs-lightweight editor(with bunch of useful plugin and themes available)

i am using spacemacs (extended Emacs) that supports EVIL,ORG mode,python mode,documentation,etc