.pickle file created myself on raspberry pi using python, 'Permission Denied [Errno 13]' when using Mac OS Sierra to access/alter

Question

I have created a shared file on my local network with the intent of setting up a messaging service. I have tried using chmod 777 to change file and directory permissions but this has not resolved the issue. Using the Pi script to send messages works perfectly fine, but when trying to send a message from Mac to the Pi, the error: 'PermissionError: [Errno 13] Permission denied: 'test_message.pickle'' appears.

def send():
        os.chdir(r'/Volumes/share/')
        os.remove('test_message.pickle')
        f = open('test_message.pickle','wb')
        p.dump(app.text.get("1.0",END),f)
        f.close()