Writing a dictionary and a list class in a pickle file using python- (Error: Cant pickle local object)

Question

I need to read a model file modify the weight and write back to an updated model file using the pickle library. The data consists of a dictionary and a ndarray list. While doing that I can successfully read the value and modify it but can not dump it using pickle.dump. The code is as below,

import pickle

# Viewing the element tye in the pickle file
with open('/content/Training/PPO_model_EV.pkl', 'rb') as f:
    data = pickle.load(f)

# Viewing the element type in the pickle file and data
k=0
for i in data:
  if k==0:
    i_dict=i
    print(type(i_dict),i_dict)
  if k==1:
    i_list=i
    print(type(i_list),i_list)
  k=k+1

# Write the value back to another pickle file
pickle_out = open("/content/Modified_model.pkl","wb")
pickle.dump((i_dict,i_list),pickle_out)
pickle_out .close()

Here,

dict: i_dict (16 items) {'gamma': 0.99, 'n_steps': 128, 'vf_coef': 0.5, 'ent_coef': 0.01, 'max_grad_norm': 0.5, ...}

list: i_list (15 items) [ndarray with shape (60, 64), ndarray with shape (64,), ndarray with shape (60, 64), ndarray with shape (64,), ndarray with shape (64, 64), ...]

The output of the code is as follows,

<class 'dict'> {'gamma': 0.99, 'n_steps': 128, 'vf_coef': 0.5, 'ent_coef': 0.01, 'max_grad_norm': 0.5, 'learning_rate': <function constfn.<locals>.func at 0x7f71599600e0>, 'lam': 0.95, 'nminibatches': 4, 'noptepochs': 4, 'cliprange': <function constfn.<locals>.func at 0x7f7159960290>, 'verbose': 1, 'policy': <class '__main__.CustomPolicy'>, 'observation_space': Box(0.0, 1.0, (12, 5), float16), 'action_space': Box(-1.0, 1.0, (2,), float16), 'n_envs': 1, '_vectorize_action': False}
<class 'list'> [array([[ 0.33291984, -0.1476613 , -0.207661  , ...,  0.26993886,
        -0.4049534 ,  0.30404437],
       [-0.23681359,  0.02351136,  0.2928835 , ..., -0.30670926,
         0.06748895,  0.12044807],
       [-0.15989211,  0.03464196, -0.058044  , ..., -0.2320129 ,
        -0.04890745, -0.14575315],
       ...,
    ---------------------------------------------------------------------------
    AttributeError                            Traceback (most recent call last)
    <ipython-input-175-c7240e147380> in <module>()
         19 # Write the value back to another pickle file
         20 pickle_out = open("/content/Modified_model.pkl","wb")
    ---> 21 pickle.dump((i_dict,i_list),pickle_out)
         22 pickle_out .close()
         23 
    
    AttributeError: Can't pickle local object 'constfn.<locals>.func'
      

Any help and suggestion will be greatly appreciated.