diff --git a/ostap/io/compress_shelve.py b/ostap/io/compress_shelve.py
index 30f49152..e8043a01 100755
--- a/ostap/io/compress_shelve.py
+++ b/ostap/io/compress_shelve.py
@@ -159,7 +159,7 @@ def __init__(
         if not self.__silent :
             logger.info ( 'Open DB: %s' % dbname ) 
 
-        ## filename without extension and the extension  itself 
+        ## filename without extension and the extension itself 
         fname , ext = os.path.splitext ( dbname )
 
         self.__extension = ext
@@ -200,7 +200,7 @@ def __init__(
                 self.__actual_dbname = filename
 
         afiles = tuple ( [ self.dbname + suffix for suffix in (  '' , ',db' , '.dir' , '.pag' , '.dat' ) ] )
-        ofiles = set ( [ i for i in glob.iglob  ( self.dbname + '*' ) if i in afiles ] ) 
+        ofiles = set   ( [ i for i in glob.iglob  ( self.dbname + '*' ) if i in afiles ] ) 
 
         
         self.__opened = False
diff --git a/ostap/io/tests/test_io_dbases.py b/ostap/io/tests/test_io_dbases.py
index 9bcff63d..99cf90c6 100644
--- a/ostap/io/tests/test_io_dbases.py
+++ b/ostap/io/tests/test_io_dbases.py
@@ -41,7 +41,7 @@ def the_name ():
     item = 'LmdbDict' , CleanUp.tempdir ( prefix = 'ostap-LMDB-' ) , LmdbDict
     dbases.append ( item )
 except ImportError:
-    logger.warning ( 'LmdbDict is not accessible!' )
+    logger.warning ( 'LmdbDict    is not accessible!' )
 
 # ============================================================================
 try :
@@ -50,7 +50,7 @@ def the_name ():
     item = 'BerkeleyDB' , CleanUp.tempfile ( prefix = 'ostap-BerkeleyDB-' , suffix = '.db' ) , berkeleydb_open 
     dbases.append ( item )
 except ImportError:
-    logger.warning ( 'BerkeleyDB is not accessible!' )
+    logger.warning ( 'BerkeleyDB  is not accessible!' )
 
 # ============================================================================
 try :
@@ -59,7 +59,7 @@ def the_name ():
     item = 'BSDDB3' , CleanUp.tempfile ( prefix = 'ostap-BSDDB3-' , suffix = '.db'  ) , bsbdb3_open 
     dbases.append ( item )
 except ImportError:
-    logger.warning ( 'bsddb3 is not accessible!' )
+    logger.warning ( 'bsddb3      is not accessible!' )
    
 # ============================================================================
 try :
@@ -67,7 +67,7 @@ def the_name ():
     item = 'SqliteDict' , CleanUp.tempfile ( prefix = 'ostap-SqliteDB-' , suffix = '.sql') , SqliteDict
     dbases.append ( item )
 except ImportError:
-    logger.warning ( 'SQliteDict is not accessible!' )
+    logger.warning ( 'SQliteDict  is not accessible!' )
 
 # ============================================================================
 if ( 3,0 ) <= sys.version_info :
@@ -78,7 +78,7 @@ def gnu_open ( filename , flag = 'r' ) : return _gnu_open ( filename , flag )
         item = 'dbm.gnu' , CleanUp.tempfile ( prefix = 'ostap-GNUDB-' , suffix = '.db' ) , gnu_open
         dbases.append ( item )
     except ImportError:
-        logger.warning ( 'dbm.gnuis not accessible!' )
+        logger.warning ( 'dbm.gnu   is not accessible!' )
     # ======================================================================
     try :
         from dbm.ndbm import open as _ndbm_open
@@ -86,7 +86,7 @@ def ndbm_open ( filename , flag = 'r' ) : return _ndbm_open ( filename , flag )
         item = 'dbm.ndbm' , CleanUp.tempfile ( prefix = 'ostap-NDB-' , suffix = '.db' ) , ndbm_open
         dbases.append ( item )
     except ImportError:
-        logger.warning ( 'dbm.ndbm is not accessible!' )
+        logger.warning ( 'dbm.ndbm  is not accessible!' )
     # ======================================================================
     try :
         from dbm.dumb import open as dumb_open
diff --git a/ostap/io/tests/test_io_shelves.py b/ostap/io/tests/test_io_shelves.py
index 8c543508..e322c8b5 100755
--- a/ostap/io/tests/test_io_shelves.py
+++ b/ostap/io/tests/test_io_shelves.py
@@ -155,14 +155,14 @@ def test_shelves1():
         db_zst = zstshelve.open    ( db_zst_name  , 'r' )
     db_root = rootshelve.open      ( db_root_name , 'r' )
 
-    logger.info('SQLiteShelve #keys: %s' % len ( list ( db_sql .keys() ) ) ) 
-    logger.info('ZipShelve    #keys: %s' % len ( db_zip .keys() ) )
-    logger.info('Bz2Shelve    #keys: %s' % len ( db_bz2 .keys() ) )
+    logger.info('SQLiteShelve #keys: %s' % len ( db_sql ) ) 
+    logger.info('ZipShelve    #keys: %s' % len ( db_zip ) )
+    logger.info('Bz2Shelve    #keys: %s' % len ( db_bz2 ) )
     if lzshelve  :
-        logger.info('LzShelve     #keys: %s' % len ( db_lz  .keys() ) )
+        logger.info('LzShelve     #keys: %s' % len ( db_lz  ) )
     if zstshelve :
-        logger.info('ZstShelve    #keys: %s' % len ( db_zst .keys() ) )
-    logger.info('RootShelve   #keys: %s' % len ( db_root.keys() ) )
+        logger.info('ZstShelve    #keys: %s' % len ( db_zst ) )
+    logger.info('RootShelve   #keys: %s' % len ( db_root ) )
 
     with timing ( 'h2-read/SQL'  ) : h2_sql  = db_sql  [ 'histo-2D']
     with timing ( 'h2_read/ZIP'  ) : h2_zip  = db_zip  [ 'histo-2D']