import copy

config_overrides = {
    'nodetype': ['srnn', 'lstm', 'gru'],
    'nhidden': [1,2,3,4,5,6,8,10,12,16,20],
    'opt': ['sgd', 'rmsprop', 'adagrad', 'adamax', 'adam', 'nadam', 'adadelta'],
    'actfunc': ['softplus', 'softsign', 'tanh', 'sigmoid', 'hard_sigmoid', 'linear', 'relu'],
    'loss': ['mse', 'msle']
}

experiments = [{},]

for k,v in config_overrides.items():
    new_values = len(v)
    current_exp_len = len(experiments)
    for _ in range(new_values-1):
       experiments.extend(copy.deepcopy(experiments[:current_exp_len]))
    for validx in range(len(v)):
       for exp in experiments[validx*current_exp_len(validx+1)*current_exp_len]:
            exp[k] = v[validx]

print(len(experiments))
print([x for x in experiments[1034:1039]])

3234
[{'loss': 'mse', 'opt': 'adadelta', 'actfunc': 'sigmoid', 'nodetype': 'lstm', 'nhidden': 4}, {'loss': 'msle', 'opt': 'adadelta', 'actfunc': 'sigmoid', 'nodetype': 'lstm', 'nhidden': 4}, {'loss': 'mse', 'opt': 'sgd', 'actfunc': 'hard_sigmoid', 'nodetype': 'lstm', 'nhidden': 4}, {'loss': 'msle', 'opt': 'sgd', 'actfunc': 'hard_sigmoid', 'nodetype': 'lstm', 'nhidden': 4}, {'loss': 'mse', 'opt': 'rmsprop', 'actfunc': 'hard_sigmoid', 'nodetype': 'lstm', 'nhidden': 4}]