[Py2to3] Refactor out usage of unicode and basestring

 - Python 3 renames `unicode` type to `str` and introduces `bytes` type.
 - Python 2.7 has `bytes` but is only an alias for `str` so restricted
   to comparisons but helps keep compatibility.
 - To test for unicode string on Py2 and Py3 uses the "''.__class__" type.
 - Remove usage of utf8encode and just encode, problems with bytes being passed
   in code will be picked up faster.
 - Where possible refactor out isinstance for try..except duck-typing.

13 files changed, 40 insertions, 71 deletions

diff --git a/deluge/ui/console/cmdline/commands/info.py b/deluge/ui/console/cmdline/commands/info.py
index 84838713f..fc80d1aba 100644
--- a/deluge/ui/console/cmdline/commands/info.py
+++ b/deluge/ui/console/cmdline/commands/info.py
@@ -212,9 +212,6 @@ class Command(BaseCommand):
             def tlen(string):
                 return strwidth(format_utils.remove_formatting(string))
 
-            if not isinstance(col_filename, unicode):
-                col_filename = unicode(col_filename, 'utf-8')
-
             col_all_info = col_size + col_progress + col_priority
             # Check how much space we've got left after writing all the info
             space_left = cols - tlen(col_all_info)
diff --git a/deluge/ui/console/main.py b/deluge/ui/console/main.py
index cce63d662..7b7904c0a 100644
--- a/deluge/ui/console/main.py
+++ b/deluge/ui/console/main.py
@@ -371,8 +371,7 @@ Please use commands from the command line, e.g.:\n
             no matches are found.
 
         """
-        if not isinstance(string, unicode):
-            string = unicode(string, self.encoding)
+        deluge.common.decode_bytes(string, self.encoding)
 
         if string == '*' or string == '':
             return [tid for tid, name in self.torrents]
@@ -387,8 +386,7 @@ Please use commands from the command line, e.g.:\n
 
         matches = []
         for tid, name in self.torrents:
-            if not isinstance(name, unicode):
-                name = unicode(name, self.encoding)
+            deluge.common.decode_bytes(name, self.encoding)
             if getattr(tid, match_func, None)(string) or getattr(name, match_func, None)(string):
                 matches.append(tid)
         return matches
@@ -423,7 +421,7 @@ Please use commands from the command line, e.g.:\n
                 component.get('CmdLine').add_line(s, False)
                 self.events.append(s)
         else:
-            print(colors.strip_colors(deluge.common.utf8_encoded(s)))
+            print(colors.strip_colors(s.encode('utf8')))
 
     def write_event(self, s):
         if self.interactive:
@@ -434,7 +432,7 @@ Please use commands from the command line, e.g.:\n
                 component.get('CmdLine').add_line(s, False)
                 self.events.append(s)
         else:
-            print(colors.strip_colors(deluge.common.utf8_encoded(s)))
+            print(colors.strip_colors(s.encode('utf8')))
 
     def _migrate_config_1_to_2(self, config):
         """Create better structure by moving most settings out of dict root
diff --git a/deluge/ui/console/modes/cmdline.py b/deluge/ui/console/modes/cmdline.py
index 0eb134e6c..287791a52 100644
--- a/deluge/ui/console/modes/cmdline.py
+++ b/deluge/ui/console/modes/cmdline.py
@@ -417,10 +417,7 @@ class CmdLine(BaseMode, Commander):
 
             # Write the line
             with open(self.history_file[active_file], 'a', encoding='utf8') as _file:
-                if isinstance(text, unicode):
-                    text = text.encode(self.encoding)
-                _file.write(text)
-                _file.write(os.linesep)
+                _file.write(text + '\n')
 
             # And increment line counter
             self._hf_lines[active_file] += 1
diff --git a/deluge/ui/console/modes/torrentlist/torrentactions.py b/deluge/ui/console/modes/torrentlist/torrentactions.py
index d855aaa95..404d2c27d 100644
--- a/deluge/ui/console/modes/torrentlist/torrentactions.py
+++ b/deluge/ui/console/modes/torrentlist/torrentactions.py
@@ -131,17 +131,14 @@ def action_torrent_info(mode=None, torrent_ids=None, **kwargs):
         for field in torrent_options:
             caption = '{!info!}' + TORRENT_DATA_FIELD[field]['name']
             value = options[field]
-            field_type = type(value)
-            if field_type in [str, unicode]:
-                if not isinstance(value, basestring):
-                    value = str(value)
+            if isinstance(value, ''.__class__):
                 option_popup.add_text_input(field, caption, value)
-            elif field_type == bool:
-                choices = (['Yes', 'No'], [True, False], [True, False].index(options[field]))
+            elif isinstance(value, bool):
+                choices = (['Yes', 'No'], [True, False], [True, False].index(value))
                 option_popup.add_select_input(field, caption, choices[0], choices[1], choices[2])
-            elif field_type == float:
+            elif isinstance(value, float):
                 option_popup.add_float_spin_input(field, caption, value=value, min_val=-1)
-            elif field_type == int:
+            elif isinstance(value, int):
                 option_popup.add_int_spin_input(field, caption, value=value, min_val=-1)
 
         mode.push_popup(option_popup)
diff --git a/deluge/ui/console/modes/torrentlist/torrentview.py b/deluge/ui/console/modes/torrentlist/torrentview.py
index 98b18f1ec..6ef1d7e83 100644
--- a/deluge/ui/console/modes/torrentlist/torrentview.py
+++ b/deluge/ui/console/modes/torrentlist/torrentview.py
@@ -237,18 +237,15 @@ class TorrentView(InputKeyHandler):
             # and if it's a string
             first_element = state[state.keys()[0]]
             if field in first_element:
-                is_string = isinstance(first_element[field], basestring)
-
                 def sort_key(s):
-                    return state.get(s)[field]
-
-                def sort_key2(s):
-                    return state.get(s)[field].lower()
+                    try:
+                        # Sort case-insensitively but preserve A>a order.
+                        return state.get(s)[field].lower()
+                    except AttributeError:
+                        # Not a string.
+                        return state.get(s)[field]
 
-                # If it's a string, sort case-insensitively but preserve A>a order
                 to_sort = sorted(to_sort, _queue_sort, sort_key, reverse)
-                if is_string:
-                    to_sort = sorted(to_sort, _queue_sort, sort_key2, reverse)
 
             if field == 'eta':
                 to_sort = sorted(to_sort, key=lambda s: state.get(s)['eta'] == 0)
diff --git a/deluge/ui/console/utils/colors.py b/deluge/ui/console/utils/colors.py
index 50ec6d40c..17119e71a 100644
--- a/deluge/ui/console/utils/colors.py
+++ b/deluge/ui/console/utils/colors.py
@@ -131,7 +131,7 @@ def strip_colors(line):
     return line
 
 
-def get_line_length(line, encoding='UTF-8'):
+def get_line_length(line):
     """
     Returns the string length without the color formatting.
 
@@ -139,9 +139,6 @@ def get_line_length(line, encoding='UTF-8'):
     if line.count('{!') != line.count('!}'):
         raise BadColorString('Number of {! is not equal to number of !}')
 
-    if isinstance(line, unicode):
-        line = line.encode(encoding, 'replace')
-
     # Remove all the color tags
     line = strip_colors(line)
 
@@ -150,7 +147,7 @@ def get_line_length(line, encoding='UTF-8'):
     return len(line)
 
 
-def get_line_width(line, encoding='UTF-8'):
+def get_line_width(line):
     """
     Get width of string considering double width characters
 
@@ -158,9 +155,6 @@ def get_line_width(line, encoding='UTF-8'):
     if line.count('{!') != line.count('!}'):
         raise BadColorString('Number of {! is not equal to number of !}')
 
-    if isinstance(line, unicode):
-        line = line.encode(encoding, 'replace')
-
     # Remove all the color tags
     line = strip_colors(line)
 
@@ -180,9 +174,6 @@ def parse_color_string(s, encoding='UTF-8'):
     if s.count('{!') != s.count('!}'):
         raise BadColorString('Number of {! is not equal to number of !}')
 
-    if isinstance(s, unicode):
-        s = s.encode(encoding, 'replace')
-
     ret = []
     last_color_attr = None
     # Keep track of where the strings
diff --git a/deluge/ui/console/utils/format_utils.py b/deluge/ui/console/utils/format_utils.py
index f259061d6..ac7fc2539 100644
--- a/deluge/ui/console/utils/format_utils.py
+++ b/deluge/ui/console/utils/format_utils.py
@@ -11,8 +11,7 @@ from __future__ import unicode_literals
 
 import re
 from collections import deque
-from unicodedata import normalize as ud_normalize
-from unicodedata import east_asian_width
+from unicodedata import east_asian_width, normalize
 
 import deluge.common
 from deluge.ui.common import FILE_PRIORITY
@@ -88,7 +87,7 @@ def trim_string(string, w, have_dbls):
         idx = 0
         while width < w:
             chrs.append(string[idx])
-            if east_asian_width(string[idx]) in ['W', 'F']:
+            if east_asian_width(string[idx]) in 'WF':
                 width += 2
             else:
                 width += 1
@@ -102,14 +101,13 @@ def trim_string(string, w, have_dbls):
 
 
 def format_column(col, lim):
-    dbls = 0
-    # Chosen over isinstance(col, unicode) and col.__class__ == unicode
-    # for speed - it's ~3 times faster for non-unicode strings and ~1.5
-    # for unicode strings.
-    if col.__class__ is unicode:
+    try:
         # might have some double width chars
-        col = ud_normalize('NFC', col)
+        col = normalize('NFC', col)
         dbls = sum(east_asian_width(c) in 'WF' for c in col)
+    except TypeError:
+        dbls = 0
+
     size = len(col) + dbls
     if size >= lim - 1:
         return trim_string(col, lim, dbls > 0)
@@ -239,8 +237,6 @@ def strwidth(string):
     """
     Measure width of a string considering asian double width characters
     """
-    if not isinstance(string, unicode):
-        string = unicode(string, 'utf-8')
     return sum([1 + (east_asian_width(char) in ['W', 'F']) for char in string])
 
 
diff --git a/deluge/ui/console/widgets/inputpane.py b/deluge/ui/console/widgets/inputpane.py
index e76708f21..cf53b48ea 100644
--- a/deluge/ui/console/widgets/inputpane.py
+++ b/deluge/ui/console/widgets/inputpane.py
@@ -299,7 +299,7 @@ class BaseInputPane(InputKeyHandler):
 
             if ipt.default_col != -1:
                 default_col = int(ipt.default_col)
-                if isinstance(ipt.default_col, basestring) and ipt.default_col[0] in ['+', '-']:
+                if isinstance(ipt.default_col, ''.__class__) and ipt.default_col[0] in ['+', '-']:
                     col += default_col
                     cursor_offset += default_col
                     field_width -= default_col  # Increase to col must be reflected here
diff --git a/deluge/ui/gtkui/listview.py b/deluge/ui/gtkui/listview.py
index e61162a6f..2b3f7b1e5 100644
--- a/deluge/ui/gtkui/listview.py
+++ b/deluge/ui/gtkui/listview.py
@@ -15,6 +15,7 @@ import gtk
 from gobject import SIGNAL_RUN_LAST, TYPE_NONE, signal_new
 from gtk.gdk import Event  # pylint: disable=ungrouped-imports
 
+from deluge.common import decode_bytes
 from deluge.ui.gtkui.common import load_pickled_state_file, save_pickled_state_file
 
 signal_new('button-press-event', gtk.TreeViewColumn, SIGNAL_RUN_LAST, TYPE_NONE, (Event,))
@@ -320,7 +321,7 @@ class ListView(object):
         try:
             self.columns[name].column.set_visible(widget.get_active())
         except KeyError:
-            self.columns[unicode(name)].column.set_visible(widget.get_active())
+            self.columns[decode_bytes(name)].column.set_visible(widget.get_active())
         return
 
     def on_treeview_header_right_clicked(self, column, event):
diff --git a/deluge/ui/gtkui/preferences.py b/deluge/ui/gtkui/preferences.py
index ab5954cc7..2e424549c 100644
--- a/deluge/ui/gtkui/preferences.py
+++ b/deluge/ui/gtkui/preferences.py
@@ -401,20 +401,20 @@ class Preferences(component.Component):
         # Update the widgets accordingly
         for key in core_widgets:
             modifier = core_widgets[key][0]
-            if isinstance(key, basestring):
+            try:
                 widget = self.builder.get_object(key)
-            else:
+            except TypeError:
                 widget = key
 
             widget.set_sensitive(self.is_connected)
 
             if self.is_connected:
                 value = core_widgets[key][1]
-                from types import FunctionType
-                if isinstance(value, FunctionType):
-                    value = value()
-                elif isinstance(value, basestring):
+                try:
                     value = self.core_config[value]
+                except KeyError:
+                    if callable(value):
+                        value = value()
             elif modifier:
                 value = {'active': False, 'not_active': False, 'value': 0, 'text': '', 'path_chooser': ''}[modifier]
 
@@ -433,9 +433,9 @@ class Preferences(component.Component):
 
         if self.is_connected:
             for key in core_widgets:
-                if isinstance(key, basestring):
+                try:
                     widget = self.builder.get_object(key)
-                else:
+                except TypeError:
                     widget = key
                 # Update the toggle status if necessary
                 self.on_toggle(widget)
diff --git a/deluge/ui/translations_util.py b/deluge/ui/translations_util.py
index 6803d55a2..656cabd1c 100644
--- a/deluge/ui/translations_util.py
+++ b/deluge/ui/translations_util.py
@@ -70,7 +70,6 @@ def set_language(lang):
     :param lang: the language, e.g. "en", "de" or "en_GB"
     :type lang: str
     """
-    lang = str(lang)
     # Necessary to set these environment variables for GtkBuilder
     deluge.common.set_env_variable('LANGUAGE', lang)  # Windows/Linux
     deluge.common.set_env_variable('LANG', lang)  # For OSX
diff --git a/deluge/ui/web/auth.py b/deluge/ui/web/auth.py
index be862a11d..d5a439d42 100644
--- a/deluge/ui/web/auth.py
+++ b/deluge/ui/web/auth.py
@@ -18,8 +18,6 @@ from email.utils import formatdate
 
 from twisted.internet.task import LoopingCall
 
-from deluge.common import utf8_encoded
-
 log = logging.getLogger(__name__)
 
 
@@ -143,7 +141,7 @@ class Auth(JSONComponent):
             log.debug('Received a password via the 1.2-dev auth method')
             m = hashlib.md5()
             m.update(config['pwd_salt'])
-            m.update(utf8_encoded(password))
+            m.update(password.encode('utf8'))
             if m.hexdigest() == config['pwd_md5']:
                 # We want to move the password over to sha1 and remove
                 # the old passwords from the config file.
@@ -163,7 +161,7 @@ class Auth(JSONComponent):
             from base64 import decodestring
             m = hashlib.md5()
             m.update(decodestring(config['old_pwd_salt']))
-            m.update(utf8_encoded(password))
+            m.update(password.encode('utf8'))
             if m.digest() == decodestring(config['old_pwd_md5']):
 
                 # We want to move the password over to sha1 and remove
@@ -179,7 +177,7 @@ class Auth(JSONComponent):
             log.debug('Received a password via the 1.2 auth method')
             s = hashlib.sha1()
             s.update(config['pwd_salt'])
-            s.update(utf8_encoded(password))
+            s.update(password.encode('utf8'))
             if s.hexdigest() == config['pwd_sha1']:
                 return True
 
@@ -249,7 +247,7 @@ class Auth(JSONComponent):
         log.debug('Changing password')
         salt = hashlib.sha1(os.urandom(32)).hexdigest()
         s = hashlib.sha1(salt)
-        s.update(utf8_encoded(new_password))
+        s.update(new_password.encode('utf8'))
         self.config['pwd_salt'] = salt
         self.config['pwd_sha1'] = s.hexdigest()
         return True
diff --git a/deluge/ui/web/json_api.py b/deluge/ui/web/json_api.py
index 96cf80aaf..0e66408c8 100644
--- a/deluge/ui/web/json_api.py
+++ b/deluge/ui/web/json_api.py
@@ -897,8 +897,6 @@ class WebApi(JSONComponent):
             if key in ['sessions', 'pwd_salt', 'pwd_sha1']:
                 log.warn('Ignored attempt to overwrite web config key: %s', key)
                 continue
-            if isinstance(config[key], basestring):
-                config[key] = config[key].encode('utf8')
             web_config[key] = config[key]
 
     @export