pylint: fix no-else-raise cases

Fix all cases of R1720 no-else-raise.

Part of #270

Author: DifferentialOrange

tarantool/connection.py

@@ -1114,15 +1114,15 @@ def _recv(self, to_read):
                     "Lost connection to server during query"
                 )
                 raise NetworkError(err) from exc
-            else:
-                if len(tmp) == 0:
-                    err = socket.error(
-                        errno.ECONNRESET,
-                        "Lost connection to server during query"
-                    )
-                    raise NetworkError(err)
-                to_read -= len(tmp)
-                buf += tmp
+
+            if len(tmp) == 0:
+                err = socket.error(
+                    errno.ECONNRESET,
+                    "Lost connection to server during query"
+                )
+                raise NetworkError(err)
+            to_read -= len(tmp)
+            buf += tmp
         return buf
 
     def _read_response(self):

tarantool/schema.py

@@ -240,7 +240,7 @@ def fetch_space(self, space):
             raise SchemaError(
                 'Some strange output from server: \n' + str(space_row)
             )
-        elif len(space_row) == 0 or not space_row[0]:
+        if len(space_row) == 0 or not space_row[0]:
             # We can't find space with this name or id
             temp_name = 'name' if isinstance(space, str) else 'id'
             errmsg = f"There's no space with {temp_name} '{space}'"
@@ -352,7 +352,7 @@ def fetch_index(self, space_object, index):
             raise SchemaError(
                 'Some strange output from server: \n' + str(index_row)
             )
-        elif len(index_row) == 0 or not index_row[0]:
+        if len(index_row) == 0 or not index_row[0]:
             # We can't find index with this name or id
             temp_name = 'name' if isinstance(index, str) else 'id'
             errmsg = (f"There's no index with {temp_name} '{index}'"