Identity is not the same thing as equality in Python so use ==/!= to compare str, bytes, and int literals. In Python >= 3.8, these instances will raise __SyntaxWarnings__ so it is best to fix them now. https://docs.python.org/3.8/whatsnew/3.8.html#porting-to-python-3-8

% __python__
```
>>> dtype = "float"
>>> dtype += "16"
>>> dtype == "float16"
True
>>> dtype is "float16"
False
>>> 0 == 0.0
True
>>> 0 is 0.0
False
```