Add .zst support to save api and AFNI/MINC formats

Author: vanandrew

nibabel/brikhead.py

@@ -494,6 +494,11 @@ class AFNIImage(SpatialImage):
     makeable = False
     rw = False
     ImageArrayProxy = AFNIArrayProxy
+    try: # If pyzstd installed., add .zst suffix
+        import pyzstd
+        _compressed_suffixes = (*_compressed_suffixes, '.zst')
+    except ImportError:
+        pass
 
     @classmethod
     def from_file_map(klass, file_map, *, mmap=True, keep_file_open=None):

nibabel/loadsave.py

@@ -19,6 +19,12 @@
 from .arrayproxy import is_proxy
 from .deprecated import deprecate_with_version
 
+_compressed_suffixes = ('.gz', '.bz2')
+try: # If pyzstd installed., add .zst suffix
+    import pyzstd
+    _compressed_suffixes = (*_compressed_suffixes, '.zst')
+except ImportError:
+    pass
 
 def load(filename, **kwargs):
     r""" Load file given filename, guessing at file type
@@ -103,7 +109,7 @@ def save(img, filename):
         return
 
     # Be nice to users by making common implicit conversions
-    froot, ext, trailing = splitext_addext(filename, ('.gz', '.bz2'))
+    froot, ext, trailing = splitext_addext(filename, _compressed_suffixes)
     lext = ext.lower()
 
     # Special-case Nifti singles and Pairs

nibabel/minc1.py

@@ -317,6 +317,11 @@ class Minc1Image(SpatialImage):
     valid_exts = ('.mnc',)
     files_types = (('image', '.mnc'),)
     _compressed_suffixes = ('.gz', '.bz2')
+    try: # If pyzstd installed., add .zst suffix
+        import pyzstd
+        _compressed_suffixes = (*_compressed_suffixes, '.zst')
+    except ImportError:
+        pass
 
     makeable = True
     rw = False