This is the code I have so far, but my input can be a boolean or a list of size 2 (str and int). Here is part of the code :
# In the function arguments
structured: Union[List[bool], bool]
grid: Union[List[bool], bool]
# instructions
if structured is False or grid is False:
self.structured: bool = False
else:
self.structured = True
self.eltType = structured[0]
self.Lx = grid[0]
self.Ly = grid[1]
self.Lz = structured[1]
But I get the error :
error: Value of type "Union[List[bool], Literal[True]]" is not indexable [index]
The thing is that the first if statement tackles the case when grid/structured are bool and the else when they are arrays.
My second question is how to annotate an array that contains a str and an int.
List[Union[str,int]] # maybe ?
Your condition, if false, doesn't guarantee for type-narrowing purposes that either variable is a list, only that at least one of them equals False.
Use a more explicit condition:
self.structured: bool
if isinstance(structured, list) and isinstance(structured, list):
self.structured = True
self.eltType = structured[0]
self.Lx = grid[0]
self.Ly = grid[1]
self.Lz = structured[1]
else:
self.structured = False
Since a value of True doesn't seem to make sense for either variable, consider a more constrained type like Optional[list[bool]] instead. Then you only have either None or a (not necessarily long enough) list.
# In the function arguments
structured: Optional[List[bool]]
grid: Optional[List[bool]]
self.structured: bool
if structured is not None and grid is not None:
# Both must be lists
self.structured = True
self.eltType = structured[0]
self.Lx = grid[0]
self.Ly = grid[1]
self.Lz = structured[1]
else:
# One of them might be a list, but we'll ignore it.
self.structured: bool = False