Either way is okay in python. I would personally prefer "". but again, either way is okay
>>>x = None
>>>print(x)
None
>>>type(x)
>>>x = "hello there"
>>>print(x)
hello there
>>>type(x)
>>>
>>>x = ""
>>>print(x)
>>>type(x)
>>>x = "hello there"
>>>type(x)
>>>print(x)
hello there