MNT: Replace format() calls with f strings in asserts

src/metpy/io/nexrad.py

@@ -1848,10 +1848,10 @@ def _unpack_symblock(self, start, offset):
         log.debug('Symbology block info: %s', blk)
 
         self.sym_block = []
-        assert blk.divider == -1, ('Bad divider for symbology block: {:d} should be -1'
-                                   .format(blk.divider))
-        assert blk.block_id == 1, ('Bad block ID for symbology block: {:d} should be 1'
-                                   .format(blk.block_id))
+        assert blk.divider == -1, (f'Bad divider for symbology block: {blk.divider} should '
+                                   'be -1')
+        assert blk.block_id == 1, (f'Bad block ID for symbology block: {blk.block_id} should '
+                                   'be 1')
         for _ in range(blk.nlayer):
             layer_hdr = self._buffer.read_struct(self.sym_layer_fmt)
             assert layer_hdr.divider == -1
@@ -1872,10 +1872,10 @@ def _unpack_symblock(self, start, offset):
     def _unpack_graphblock(self, start, offset):
         self._buffer.jump_to(start, offset)
         hdr = self._buffer.read_struct(self.graph_block_fmt)
-        assert hdr.divider == -1, ('Bad divider for graphical block: {:d} should be -1'
-                                   .format(hdr.divider))
-        assert hdr.block_id == 2, ('Bad block ID for graphical block: {:d} should be 1'
-                                   .format(hdr.block_id))
+        assert hdr.divider == -1, (f'Bad divider for graphical block: {hdr.divider} should '
+                                   f'be -1')
+        assert hdr.block_id == 2, (f'Bad block ID for graphical block: {hdr.block_id} should '
+                                   'be 1')
         self.graph_pages = []
         for page in range(hdr.num_pages):
             page_num = self._buffer.read_int(2, 'big', signed=False)