fix(typing): more annotations cleanup.

src/mrinufft/extras/smaps.py

@@ -1,10 +1,11 @@
 """SMaps module for sensitivity maps estimation."""
 
+from __future__ import annotations
+
 from mrinufft.density.utils import flat_traj
 from mrinufft.operators.base import get_array_module
 from .utils import register_smaps
 import numpy as np
-from typing import Tuple
 
 
 def _extract_kspace_center(
@@ -102,10 +103,10 @@ def low_frequency(
     shape,
     kspace_data,
     backend,
-    threshold: float | Tuple[float, ...] = 0.1,
+    threshold: float | tuple[float, ...] = 0.1,
     density=None,
     window_fun: str = "ellipse",
-    blurr_factor: float | Tuple[float, ...] = 0.0,
+    blurr_factor: float | tuple[float, ...] = 0.0,
     mask: bool = False,
 ):
     """

src/mrinufft/io/nsp.py

@@ -47,9 +47,9 @@ def write_gradients(
         Initial positions. Shape (num_shots, dimension).
     grad_filename : str
         Gradient filename.
-    img_size : Tuple[int, ...]
+    img_size : tuple[int, ...]
         Image size.
-    FOV : Tuple[float, ...]
+    FOV : tuple[float, ...]
         Field of view.
     in_out : bool, optional
         Whether it is In-Out trajectory?, by default True
@@ -61,7 +61,7 @@ def write_gradients(
         Trajectory versioning, by default 4.2
     recon_tag : float, optional
         Reconstruction tag for online recon, by default 1.1
-    timestamp : Optional[float], optional
+    timestamp : float, optional
         Timestamp of trajectory, by default None
     keep_txt_file : bool, optional
         Whether to keep the text file used temporarily which holds data pushed to

src/mrinufft/io/siemens.py

@@ -1,16 +1,17 @@
 """Siemens specific rawdat reader, wrapper over pymapVBVD."""
 
+from __future__ import annotations
+
 import numpy as np
-from typing import Optional
 
 
 def read_siemens_rawdat(
     filename: str,
     removeOS: bool = False,
     squeeze: bool = True,
     return_twix: bool = True,
-    slice_num: Optional[int] = None,
-    contrast_num: Optional[int] = None,
+    slice_num: int | None = None,
+    contrast_num: int | None = None,
 ):  # pragma: no cover
     """Read raw data from a Siemens MRI file.