Fix issue with permission error

Author: matteobachetti

stingray/utils.py

@@ -2413,12 +2413,14 @@ def _int_sum_non_zero(array):
     return sum
 
 
-def fits_open_including_remote(filename, **kwargs):
-    """Open a FITS file, including remote files with anonymous access if needed.
+def fits_open_remote(filename, **kwargs):
+    """Open a remote FITS file.
 
     This function attempts to open a FITS file using `astropy.io.fits.open`. If a
     `PermissionError` is raised and the filename appears to be a remote URL,
-    it retries opening the file with anonymous access using fsspec.
+    it retries opening the file with fsspec.
+
+    Requires the `botocore` package to be installed.
 
     Parameters
     ----------
@@ -2438,11 +2440,40 @@ def fits_open_including_remote(filename, **kwargs):
         If the file cannot be opened and anonymous access is not possible or fails.
 
     """
+    import botocore
 
     try:
+        # This will work for local files and remote files with proper permissions
         return fits.open(filename, **kwargs)
-    except PermissionError as e:
+    except (PermissionError, botocore.exceptions.NoCredentialsError) as e:
         if "://" in filename:
-            logger.info(f"Permission denied for {filename}, trying anonymous access.")
-            return fits.open(filename, fsspec_kwargs={"anon": True}, use_fsspec=True, **kwargs)
+            logger.info(f"Permission denied for {filename}, trying with fsspec.")
+            return fits.open(filename, use_fsspec=True, fsspec_kwargs={"anon": True}, **kwargs)
         raise e
+
+
+def fits_open_including_remote(filename, **kwargs):
+    """Open a FITS file, including remote files with anonymous access if needed.
+
+    If the filename appears to be a remote URL, it calls `fits_open_remote` to handle
+    potential permission issues. Otherwise, it opens the file directly with
+    `astropy.io.fits.open`.
+
+    Parameters
+    ----------
+    filename : str
+        The path or URL to the FITS file to open. Can be a local file path or a remote URL.
+    **kwargs
+        Additional keyword arguments passed to `astropy.io.fits.open`.
+
+    Returns
+    -------
+    hdulist : astropy.io.fits.HDUList
+        The opened FITS file as an HDUList object.
+
+    """
+
+    if "://" in filename:
+        return fits_open_remote(filename, **kwargs)
+
+    return fits.open(filename, **kwargs)