better type hinting

src/pypelines/__init__.py

-__version__ = "0.0.21"
+__version__ = "0.0.22"
 
 from . import loggs
 from .pipes import *

src/pypelines/pipelines.py

-from typing import Callable, Type, Iterable, Protocol, TYPE_CHECKING
+from typing import Callable, Type, Dict, Iterable, Protocol, TYPE_CHECKING
 
 import os
 
@@ -10,6 +10,7 @@ if TYPE_CHECKING:
 
 class Pipeline:
     use_celery = False
+    pipes: Dict[str, BasePipe]
 
     def __init__(self, name: str, conf_path=None, use_celery=False):
         self.pipeline_name = name
@@ -20,7 +21,7 @@ class Pipeline:
         if use_celery:
             self.configure_celery()
 
-    def register_pipe(self, pipe_class: "BasePipe") -> "BasePipe":
+    def register_pipe(self, pipe_class: Type["BasePipe"]) -> Type["BasePipe"]:
         """Wrapper to instanciate and attache a a class inheriting from BasePipe it to the Pipeline instance.
         The Wraper returns the class without changing it."""
         instance = pipe_class(self)
@@ -43,7 +44,7 @@ class Pipeline:
         self.resolved = False
         return pipe_class
 
-    def resolve_instance(self, instance_name: str) -> "BaseStep":
+    def resolve_instance(self, instance_name: str) -> Type["BaseStep"]:
         pipe_name, step_name = instance_name.split(".")
         try:
             pipe = self.pipes[pipe_name]

src/pypelines/pipes.py

@@ -8,7 +8,8 @@ import inspect, hashlib
 
 from abc import ABCMeta, abstractmethod
 
-from typing import Callable, Type, Iterable, Protocol, TYPE_CHECKING, Literal
+from typing import Callable, Type, Iterable, Protocol, TYPE_CHECKING, Literal, Dict
+from types import MethodType
 
 if TYPE_CHECKING:
     from .pipelines import Pipeline
@@ -21,38 +22,40 @@ class BasePipe(metaclass=ABCMeta):
 
     single_step: bool = False  # a flag to tell the initializer to bind the unique step of this pipe in place
     # of the pipe itself, to the registered pipeline.
-    step_class: BaseStep = BaseStep
-    disk_class: BaseDiskObject = BaseDiskObject
-    multisession_class: BaseMultisessionAccessor = BaseMultisessionAccessor
+    step_class: Type[BaseStep] = BaseStep
+    disk_class: Type[BaseDiskObject] = BaseDiskObject
+    multisession_class: Type[BaseMultisessionAccessor] = BaseMultisessionAccessor
+
+    steps: Dict[str, BaseStep]
 
     def __init__(self, parent_pipeline: "Pipeline") -> None:
         self.pipeline = parent_pipeline
         self.pipe_name = self.__class__.__name__
 
-        self.steps = {}
+        _steps: Dict[str, MethodType] = {}
         # this loop populates self.steps dictionnary from the instanciated (bound) step methods.
         for step_name, step in inspect.getmembers(self, predicate=inspect.ismethod):
             if getattr(step, "is_step", False):
-                self.steps[step_name] = step
+                _steps[step_name] = step
 
-        if len(self.steps) < 1:
+        if len(_steps) < 1:
             raise ValueError(
                 f"You should register at least one step class with @stepmethod in {self.pipe_name} class."
-                f" { self.steps = }"
+                f" { _steps = }"
             )
 
-        if len(self.steps) > 1 and self.single_step:
+        if len(_steps) > 1 and self.single_step:
             raise ValueError(
                 f"Cannot set single_step to True if you registered more than one step inside {self.pipe_name} class."
-                f" { self.steps = }"
+                f" { _steps = }"
             )
 
         number_of_steps_with_requirements = 0
-        for step in self.steps.values():
+        for step in _steps.values():
             if len(step.requires):
                 number_of_steps_with_requirements += 1
 
-        if number_of_steps_with_requirements < len(self.steps) - 1:
+        if number_of_steps_with_requirements < len(_steps) - 1:
             raise ValueError(
                 "Steps of a single pipe must be linked in hierarchical order : Cannot have a single pipe with N steps"
                 " (N>1) and have no `requires` specification for at least N-1 steps."
@@ -60,7 +63,8 @@ class BasePipe(metaclass=ABCMeta):
 
         # this loop populates self.steps and replacs the bound methods with usefull Step objects.
         # They must inherit from BaseStep
-        for step_name, step in self.steps.items():
+        self.steps = {}
+        for step_name, step in _steps.items():
             step = self.step_class(self.pipeline, self, step)  # , step_name)
             self.steps[step_name] = step  # replace the bound_method by a step_class using that bound method,
             # so that we attach the necessary components to it.

src/pypelines/steps.py

@@ -53,6 +53,7 @@ def stepmethod(requires=[], version=None, do_dispatch=True, on_save_callbacks=[]
 
 
 class BaseStep:
+
     def __init__(
         self,
         pipeline: "Pipeline",