You may run python debugger and investigate object obj which contains all information about the optimization procedure:

import cPickle as pickle

model_path = 'net_student_(2,)-3.p'  # 'gp-deep-4.p', etc.
obj = pickle.load(open(model_path, 'rb'))


...

if you are interested in particular GP/GPEFS population, then use:

import cPickle as pickle

model_path = 'gp-deep-4.p'  # or other GP/GPEFS variants
obj = pickle.load(open(model_path, 'rb'))
pop = obj['best_gpefs'].population

