Initialize a string variable in Python: “” or None?

Question

Suppose I have a class with a string instance attribute. Should I initialize this attribute with \"\" value or None? Is either

Answer 1

If not having a value has a meaning in your program (e.g. an optional value), you should use None. That's its purpose anyway.

If the value must be provided by the caller of __init__, I would recommend not to initialize it.

If "" makes sense as a default value, use it.

In Python the type is deduced from the usage. Hence, you can change the type by just assigning a value of another type.

>>> x = None
>>> print type(x)

>>> x = "text"
>>> print type(x)

>>> x = 42
>>> print type(x)