fix

pygmt/clib/session.py

@@ -34,8 +34,6 @@
  tempfile_from_image,
 )
 
-__libgmt__ = load_libgmt()
-
 FAMILIES = [
  "GMT_IS_DATASET", # Entity is a data table
  "GMT_IS_GRID", # Entity is a grid
@@ -89,6 +87,9 @@
  np.datetime64: "GMT_DATETIME",
 }
 
+# load the GMT library outside of the Session class so it's loaded once.
+_libgmt = load_libgmt()
+
 
 class Session:
  """
@@ -310,7 +311,7 @@ def get_libgmt_func(self, name, argtypes=None, restype=None):
  <class 'ctypes.CDLL.__init__.<locals>._FuncPtr'>
  """
  if not hasattr(self, "_libgmt"):
- self._libgmt = __libgmt__
+ self._libgmt = _libgmt
  function = getattr(self._libgmt, name)
  if argtypes is not None:
  function.argtypes = argtypes