rf: Defer pybids imports

Author: effigies

templateflow/client.py

@@ -29,8 +29,6 @@
 from json import loads
 from pathlib import Path
 
-from bids.layout import Query
-
 from .conf.cache import CacheConfig, TemplateFlowCache
 
 
@@ -113,6 +111,8 @@ def ls(self, template, **kwargs):
         []
 
         """
+        from bids.layout import Query
+
         # Normalize extensions to always have leading dot
         if 'extension' in kwargs:
             kwargs['extension'] = _normalize_ext(kwargs['extension'])

templateflow/conf/cache.py

@@ -5,9 +5,12 @@
 from pathlib import Path
 from warnings import warn
 
-from .bids import Layout
 from .env import env_to_bool, get_templateflow_home
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from bids.layout import BIDSLayout
+
 
 @dataclass
 class CacheConfig:
@@ -98,11 +101,13 @@ def cached(self) -> bool:
         return self.config.root.is_dir() and any(self.config.root.iterdir())
 
     @cached_property
-    def layout(self) -> Layout:
+    def layout(self) -> BIDSLayout:
         import re
 
         from bids.layout.index import BIDSLayoutIndexer
 
+        from .bids import Layout
+
         self.ensure()
         return Layout(
             self.config.root,