Am 29.10.19 um 01:31 schrieb Changbin Du:
>> But is it, really? I agree with Jon about the distinction between None
>> and '' being confusing.
>>
> Here python is different from C. Both empty string and None are False in python.
> Note such condition is common in python.
The one is a empty string str(''), its bool('') value is False.
| >>> type(''), bool('')
| (<class 'str'>, False)
The other is a NoneType, its bool(None) value is False.
| >>> type(None), bool(None)
| (<class 'NoneType'>, False)
None often used like NULL (pointer). E.g if a function does not give an explicit
return value, the returned value is None.
| >>> def foo():
| ... pass
| ...
| >>> print(foo())
| None
-- Markus --