Replace | typing operator with Union[]

Author: robbietuk

examples/python/plot_projdata_profiles.py

@@ -17,6 +17,7 @@
 
 import argparse
 import sys
+from typing import Union
 
 import matplotlib.pyplot as plt
 import numpy as np
@@ -32,7 +33,7 @@
 }
 
 
-def get_projdata_from_file_as_numpy(filename: str) -> np.ndarray | None:
+def get_projdata_from_file_as_numpy(filename: str) -> Union[np.ndarray, None]:
     """
     Load a Projdata file and convert it to a NumPy array.
     Args:
@@ -53,7 +54,7 @@ def get_projdata_from_file_as_numpy(filename: str) -> np.ndarray | None:
         return None
 
 
-def get_projection_data_as_array(f: str | stir.ProjData) -> np.ndarray | None:
+def get_projection_data_as_array(f: Union[str, stir.ProjData]) -> Union[np.ndarray, None]:
     """
     Get the projection data from a file or object.
     Args:
@@ -80,7 +81,7 @@ def get_projection_data_as_array(f: str | stir.ProjData) -> np.ndarray | None:
 
 def compress_and_extract_1d_from_nd_array(data: np.ndarray,
                                           display_axis: int,
-                                          axes_indices: list[int | None] | None = None
+                                          axes_indices: Union[list[Union[int, None]], None] = None
                                           ) -> np.ndarray:
     """
     Generate a 1D array from an n-dimensional NumPy array based on specified parameters.
@@ -125,9 +126,9 @@ def compress_and_extract_1d_from_nd_array(data: np.ndarray,
     return data
 
 
-def plot_projdata_profiles(projection_data_list: list[stir.ProjData] | list[str],
+def plot_projdata_profiles(projection_data_list: Union[list[stir.ProjData], list[str]],
                            display_axis: int = 3,
-                           data_indices: list[int | None] | None = None,
+                           data_indices: Union[list[Union[int, None]], None] = None,
                            ) -> None:
     """
     Plots the profiles of the projection data.