In Chapter 19. here is the relevant code:
from glob import glob
files = L(glob(f'{path}/**/*.JPEG', recursive=True)).map(Path)
lbls = files.map(Self.parent.name()).unique(); lbls
If I use labmda, I would write:
lbls = files.map(labmda x: x.parent.name).unique(); lbls
I try to understand how Self.parent.name() works. By reading the underlying code for Self, I cannot figure out. If anyone understands the code below, could you provide some hints on how to interpret the logic? Thanks!
The related underlying code (in utils.py):
class _SelfCls:
def __getattr__(self,k): return getattr(_Self(),k)
# Cell
class _Self:
"An alternative to `lambda` for calling methods on passed object."
def __init__(self): self.nms,self.args,self.kwargs,self.ready = [],[],[],True
def __repr__(self): return f'self: {self.nms}({self.args}, {self.kwargs})'
def __call__(self, *args, **kwargs):
if self.ready:
x = args[0]
for n,a,k in zip(self.nms,self.args,self.kwargs):
x = getattr(x,n)
if callable(x) and a is not None: x = x(*a, **k)
return x
else:
self.args.append(args)
self.kwargs.append(kwargs)
self.ready = True
return self
def __getattr__(self,k):
if not self.ready:
self.args.append(None)
self.kwargs.append(None)
self.nms.append(k)
self.ready = False
return self
)