diff --git a/b2mirror/mirror.py b/b2mirror/mirror.py
index 701a0c3..e6e926c 100644
--- a/b2mirror/mirror.py
+++ b/b2mirror/mirror.py
@@ -1,18 +1,17 @@
 import os
 import sqlite3
-from threading import Thread
 from urllib.parse import urlparse
 from collections import namedtuple
 from b2.api import B2Api
 import sys
 from itertools import islice, filterfalse
-from concurrent.futures import ThreadPoolExecutor, Future
+from concurrent.futures import ThreadPoolExecutor
 import re
 
-#import logging
-#logging.basicConfig(level=logging.INFO)
+# import logging
+# logging.basicConfig(level=logging.INFO)
 
-FileInfo = namedtuple('FileInfo', ['abs_path', 'rel_path', 'size', 'mtime', ]) # 'fp'
+FileInfo = namedtuple('FileInfo', ['abs_path', 'rel_path', 'size', 'mtime', ])  # 'fp'
 
 
 """
@@ -27,16 +26,18 @@ The manager will iterate the set of FileInfos, and pass each to the dest
 Dest will upload the file, and inform the manager it was completed
 
 """
+
+
 class B2SyncManager(object):
 
-    workers = 10
+    workers = 15
 
     def __init__(self, source_module, dest_module, exclude_res=None):
         self.src = source_module
         self.dest = dest_module
         self.db = sqlite3.connect('./sync.db', check_same_thread=False)
         self.db.row_factory = B2SyncManager.dict_factory
-        self.db.isolation_level = None # TBD - does it hurt perf?
+        self.db.isolation_level = None  # TBD - does it hurt perf?
         self.exclude_res = [
             re.compile(r'.*\.(DS_Store|pyc|dropbox)$')
         ] + (exclude_res if exclude_res else [])
@@ -55,7 +56,7 @@ class B2SyncManager(object):
         def table_exists(table_name):
             c.execute("SELECT * FROM SQLITE_MASTER WHERE `type`='table' AND `name`=?", (table_name,))
             tables = c.fetchall()
-            if len(tables)==0:
+            if len(tables) == 0:
                 return False
             return True
 
@@ -88,15 +89,14 @@ class B2SyncManager(object):
         # Files will be marked as seen as they are processed
         # Later, unseen files will be purged
         c = self.db.cursor()
-        row = c.execute("UPDATE 'files' SET seen=0;")
+        c.execute("UPDATE 'files' SET seen=0;")
         c.close()
 
         chunk_size = 1000
 
         files_source = filterfalse(  # if rel_path matches any of the REs, the filter is True and the file is skipped
-                            lambda x: any([pattern.match(x.rel_path) for pattern in self.exclude_res]),
-                                self.src
-                            )
+                                   lambda x: any([pattern.match(x.rel_path) for pattern in self.exclude_res]),
+                                   self.src)
 
         while True:
             chunk = list(islice(files_source, chunk_size))
@@ -119,7 +119,6 @@ class B2SyncManager(object):
 
         row = c.execute("SELECT * FROM 'files' WHERE `path` = ?;", (f.rel_path,)).fetchone()
 
-
         if not row or row['mtime'] < f.mtime:
 
             print("Uploading:", f.rel_path)
@@ -129,15 +128,15 @@ class B2SyncManager(object):
                 print("Failed:", f.rel_path)
                 print("Unexpected error:", sys.exc_info()[0])
                 raise
-            #print("Ok: ", f.rel_path)
+            # print("Ok: ", f.rel_path)
 
             # The file was uploaded, commit it to the db
             c.execute("REPLACE INTO 'files' VALUES(?, ?, ?, ?);", (f.rel_path, f.mtime, f.size, 1))
-            #print("Done: ", f.rel_path)
+            # print("Done: ", f.rel_path)
 
         else:
             c.execute("UPDATE 'files' SET seen=1 WHERE `path` = ?;", (f.rel_path,)).fetchone()
-            #print("Skipping:", f.rel_path)
+            # print("Skipping:", f.rel_path)
 
         c.close()
 
@@ -175,6 +174,7 @@ class LocalProvider(Provider):
     Iterates files on local disk
     """
     max_chunk_size = 8*1024*1024
+
     def __init__(self, local_path):
         super(LocalProvider, self).__init__()
         self.local_path = local_path
@@ -190,7 +190,7 @@ class LocalProvider(Provider):
                 relative_path,
                 os.path.getsize(file_abs_path),
                 int(os.path.getmtime(file_abs_path)),
-                #open(file_abs_path, 'rb')
+                # open(file_abs_path, 'rb')
             )
         else:
             self.current_set = self.walker.__next__()
@@ -205,8 +205,8 @@ class B2Provider(Provider):
     """
 
     def __init__(self, accountId, appKey, bucketId, bucketBasePath):
-         super(B2Provider, self).__init__()
-         raise NotImplemented()
+        super(B2Provider, self).__init__()
+        raise NotImplemented()
 
 
 class Reciever(object):
@@ -219,6 +219,7 @@ class Reciever(object):
     def purge_file(self, file_path):
         raise NotImplemented()
 
+
 class B2Reciever(Reciever):
 
     max_chunk_size = 256*1024
@@ -235,7 +236,6 @@ class B2Reciever(Reciever):
         self.bucket = self.api.get_bucket_by_name(self.bucket_name)
 
     def put_file(self, file_info):
-        #print(">>> {}".format(file_info.abs_path))
         dest_path = os.path.join(self.path, file_info.rel_path).lstrip('/')
         self.bucket.upload_local_file(
                     file_info.abs_path,
@@ -246,7 +246,6 @@ class B2Reciever(Reciever):
         dest_path = os.path.join(self.path, file_path).lstrip('/')
         self.delete_by_path(dest_path)
 
-
     def delete_by_path(self, file_path):
         for f in self.bucket.list_file_versions(start_filename=file_path, max_entries=100)["files"]:
             if f["fileName"] == file_path:
@@ -262,12 +261,12 @@ def sync(source_uri, dest_uri, account_id, app_key):
     source_provider = None
     dest_receiver = None
 
-    if source.scheme == '': # Plain file URI
+    if source.scheme == '':  # Plain file URI
         source_provider = LocalProvider(source.path)
     else:
         raise Exception("Sources other than local file paths not supported")
 
-    if dest.scheme == 'b2': # Plain file URI
+    if dest.scheme == 'b2':  # Plain file URI
         dest_receiver = B2Reciever(bucket=dest.netloc, path=dest.path, account_id=account_id, app_key=app_key)
     else:
         raise Exception("Dests other than B2 URIs not yet supported")