python bindings: core — PEP8 compliance

* Fixed most of the PEP8 errors in core.py
* Those remaining may need more than little edits and are a bit
  strange (too clearly the result of a programmer who has spent far
  too much time dealing with Lisp so that for Python it looks
  ... strange).

1 files changed, 101 insertions, 77 deletions

diff --git a/lang/python/src/core.py b/lang/python/src/core.py
index 06be7f79..33a1c708 100644
--- a/lang/python/src/core.py
+++ b/lang/python/src/core.py
@@ -1,3 +1,19 @@
+# -*- coding: utf-8 -*-
+
+import re
+import os
+import warnings
+import weakref
+
+from . import gpgme
+from .errors import errorcheck, GPGMEError
+from . import constants
+from . import errors
+from . import util
+
+from __future__ import absolute_import, print_function, unicode_literals
+del absolute_import, print_function, unicode_literals
+
 # Copyright (C) 2016-2017 g10 Code GmbH
 # Copyright (C) 2004,2008 Igor Belyi <belyi@users.sourceforge.net>
 # Copyright (C) 2002 John Goerzen <jgoerzen@complete.org>
@@ -24,18 +40,6 @@ and the 'Data' class describing buffers of data.
 
 """
 
-from __future__ import absolute_import, print_function, unicode_literals
-del absolute_import, print_function, unicode_literals
-
-import re
-import os
-import warnings
-import weakref
-from . import gpgme
-from .errors import errorcheck, GPGMEError
-from . import constants
-from . import errors
-from . import util
 
 class GpgmeWrapper(object):
     """Base wrapper class
@@ -64,7 +68,7 @@ class GpgmeWrapper(object):
         return hash(repr(self.wrapped))
 
     def __eq__(self, other):
-        if other == None:
+        if other is None:
             return False
         else:
             return repr(self.wrapped) == repr(other.wrapped)
@@ -102,8 +106,10 @@ class GpgmeWrapper(object):
                            "{}get_{}".format(self._cprefix, key))
         set_func = getattr(gpgme,
                            "{}set_{}".format(self._cprefix, key))
+
         def get(slf):
             return bool(get_func(slf.wrapped))
+
         def set_(slf, value):
             set_func(slf.wrapped, bool(value))
 
@@ -116,9 +122,10 @@ class GpgmeWrapper(object):
             return get(self)
 
     _munge_docstring = re.compile(r'gpgme_([^(]*)\(([^,]*), (.*\) -> .*)')
+
     def __getattr__(self, key):
         """On-the-fly generation of wrapper methods and properties"""
-        if key[0] == '_' or self._cprefix == None:
+        if key[0] == '_' or self._cprefix is None:
             return None
 
         if key in self._boolean_properties:
@@ -160,6 +167,7 @@ class GpgmeWrapper(object):
         else:
             super(GpgmeWrapper, self).__setattr__(key, value)
 
+
 class Context(GpgmeWrapper):
     """Context for cryptographic operations
 
@@ -212,7 +220,7 @@ class Context(GpgmeWrapper):
         Helper function to retrieve the results of an operation, or
         None if SINK is given.
         """
-        if sink or data == None:
+        if sink or data is None:
             return None
         data.seek(0, os.SEEK_SET)
         return data.read()
@@ -267,10 +275,11 @@ class Context(GpgmeWrapper):
         flags |= expect_sign * constants.ENCRYPT_EXPECT_SIGN
         flags |= (not compress) * constants.ENCRYPT_NO_COMPRESS
 
-        if passphrase != None:
+        if passphrase is not None:
             old_pinentry_mode = self.pinentry_mode
             old_passphrase_cb = getattr(self, '_passphrase_cb', None)
             self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
+
             def passphrase_cb(hint, desc, prev_bad, hook=None):
                 return passphrase
             self.set_passphrase_cb(passphrase_cb)
@@ -301,7 +310,7 @@ class Context(GpgmeWrapper):
             e.results = results
             raise e
         finally:
-            if passphrase != None:
+            if passphrase is not None:
                 self.pinentry_mode = old_pinentry_mode
                 if old_passphrase_cb:
                     self.set_passphrase_cb(*old_passphrase_cb[1:])
@@ -344,10 +353,11 @@ class Context(GpgmeWrapper):
         """
         plaintext = sink if sink else Data()
 
-        if passphrase != None:
+        if passphrase is not None:
             old_pinentry_mode = self.pinentry_mode
             old_passphrase_cb = getattr(self, '_passphrase_cb', None)
             self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
+
             def passphrase_cb(hint, desc, prev_bad, hook=None):
                 return passphrase
             self.set_passphrase_cb(passphrase_cb)
@@ -365,7 +375,7 @@ class Context(GpgmeWrapper):
                          result, verify_result)
             raise e
         finally:
-            if passphrase != None:
+            if passphrase is not None:
                 self.pinentry_mode = old_pinentry_mode
                 if old_passphrase_cb:
                     self.set_passphrase_cb(*old_passphrase_cb[1:])
@@ -382,7 +392,7 @@ class Context(GpgmeWrapper):
                    for s in verify_result.signatures):
                 raise errors.BadSignatures(verify_result, results=results)
 
-        if verify and verify != True:
+        if not verify:  # was: if verify and verify != True:
             missing = list()
             for key in verify:
                 ok = False
@@ -515,14 +525,14 @@ class Context(GpgmeWrapper):
         Imports the given data into the Context.
 
         Returns:
-                -- an object describing the results of imported or updated 
+                -- an object describing the results of imported or updated
                    keys
 
         Raises:
         TypeError      -- Very rarely.
         GPGMEError     -- as signaled by the underlying library:
 
-                          Import status errors, when they occur, will usually 
+                          Import status errors, when they occur, will usually
                           be of NODATA.  NO_PUBKEY indicates something
                           managed to run the function without any
                           arguments, while an argument of None triggers
@@ -592,8 +602,8 @@ class Context(GpgmeWrapper):
         self.op_keylist_end()
 
     def create_key(self, userid, algorithm=None, expires_in=0, expires=True,
-                   sign=False, encrypt=False, certify=False, authenticate=False,
-                   passphrase=None, force=False):
+                   sign=False, encrypt=False, certify=False,
+                   authenticate=False, passphrase=None, force=False):
         """Create a primary key
 
         Create a primary key for the user id USERID.
@@ -630,9 +640,10 @@ class Context(GpgmeWrapper):
         encrypt      -- request the encryption capability (see above)
         certify      -- request the certification capability (see above)
         authenticate -- request the authentication capability (see above)
-        passphrase   -- protect the key with a passphrase (default: no passphrase)
-        force        -- force key creation even if a key with the same userid exists
-                                                          (default: False)
+        passphrase   -- protect the key with a passphrase (default: no
+                        passphrase)
+        force        -- force key creation even if a key with the same userid
+                        exists (default: False)
 
         Returns:
                      -- an object describing the result of the key creation
@@ -645,20 +656,21 @@ class Context(GpgmeWrapper):
             old_pinentry_mode = self.pinentry_mode
             old_passphrase_cb = getattr(self, '_passphrase_cb', None)
             self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
+
             def passphrase_cb(hint, desc, prev_bad, hook=None):
                 return passphrase
             self.set_passphrase_cb(passphrase_cb)
 
         try:
             self.op_createkey(userid, algorithm,
-                              0, # reserved
+                              0,  # reserved
                               expires_in,
-                              None, # extrakey
+                              None,  # extrakey
                               ((constants.create.SIGN if sign else 0)
                                | (constants.create.ENCR if encrypt else 0)
                                | (constants.create.CERT if certify else 0)
                                | (constants.create.AUTH if authenticate else 0)
-                               | (constants.create.NOPASSWD if passphrase == None else 0)
+                               | (constants.create.NOPASSWD if passphrase is None else 0)
                                | (0 if expires else constants.create.NOEXPIRE)
                                | (constants.create.FORCE if force else 0)))
         finally:
@@ -670,7 +682,8 @@ class Context(GpgmeWrapper):
         return self.op_genkey_result()
 
     def create_subkey(self, key, algorithm=None, expires_in=0, expires=True,
-                      sign=False, encrypt=False, authenticate=False, passphrase=None):
+                      sign=False, encrypt=False, authenticate=False,
+                      passphrase=None):
         """Create a subkey
 
         Create a subkey for the given KEY.  As subkeys are a concept
@@ -706,7 +719,8 @@ class Context(GpgmeWrapper):
         sign         -- request the signing capability (see above)
         encrypt      -- request the encryption capability (see above)
         authenticate -- request the authentication capability (see above)
-        passphrase   -- protect the subkey with a passphrase (default: no passphrase)
+        passphrase   -- protect the subkey with a passphrase (default: no
+                        passphrase)
 
         Returns:
                      -- an object describing the result of the subkey creation
@@ -719,19 +733,20 @@ class Context(GpgmeWrapper):
             old_pinentry_mode = self.pinentry_mode
             old_passphrase_cb = getattr(self, '_passphrase_cb', None)
             self.pinentry_mode = constants.PINENTRY_MODE_LOOPBACK
+
             def passphrase_cb(hint, desc, prev_bad, hook=None):
                 return passphrase
             self.set_passphrase_cb(passphrase_cb)
 
         try:
             self.op_createsubkey(key, algorithm,
-                                 0, # reserved
+                                 0,  # reserved
                                  expires_in,
                                  ((constants.create.SIGN if sign else 0)
                                   | (constants.create.ENCR if encrypt else 0)
                                   | (constants.create.AUTH if authenticate else 0)
                                   | (constants.create.NOPASSWD
-                                     if passphrase == None else 0)
+                                     if passphrase is None else 0)
                                   | (0 if expires else constants.create.NOEXPIRE)))
         finally:
             if util.is_a_string(passphrase):
@@ -792,8 +807,8 @@ class Context(GpgmeWrapper):
 
         """
         flags = 0
-        if uids == None or util.is_a_string(uids):
-            pass#through unchanged
+        if uids is None or util.is_a_string(uids):
+            pass  # through unchanged
         else:
             flags |= constants.keysign.LFSEP
             uids = "\n".join(uids)
@@ -883,10 +898,10 @@ class Context(GpgmeWrapper):
         GPGMEError	-- as signaled by the underlying library
 
         """
-        if key == None:
+        if key is None:
             raise ValueError("First argument cannot be None")
 
-        if sink == None:
+        if sink is None:
             sink = Data()
 
         if fnc_value:
@@ -904,6 +919,7 @@ class Context(GpgmeWrapper):
     def signers(self):
         """Keys used for signing"""
         return [self.signers_enum(i) for i in range(self.signers_count())]
+
     @signers.setter
     def signers(self, signers):
         old = self.signers
@@ -919,6 +935,7 @@ class Context(GpgmeWrapper):
     def pinentry_mode(self):
         """Pinentry mode"""
         return self.get_pinentry_mode()
+
     @pinentry_mode.setter
     def pinentry_mode(self, value):
         self.set_pinentry_mode(value)
@@ -927,6 +944,7 @@ class Context(GpgmeWrapper):
     def protocol(self):
         """Protocol to use"""
         return self.get_protocol()
+
     @protocol.setter
     def protocol(self, value):
         errorcheck(gpgme.gpgme_engine_check_version(value))
@@ -936,6 +954,7 @@ class Context(GpgmeWrapper):
     def home_dir(self):
         """Engine's home directory"""
         return self.engine_info.home_dir
+
     @home_dir.setter
     def home_dir(self, value):
         self.set_engine_info(self.protocol, home_dir=value)
@@ -948,25 +967,15 @@ class Context(GpgmeWrapper):
         # The list of functions is created using:
         #
         # $ grep '^gpgme_error_t ' obj/lang/python/python3.5-gpg/gpgme.h \
-        #   | grep -v _op_ | awk "/\(gpgme_ctx/ { printf (\"'%s',\\n\", \$2) } "
-        return ((name.startswith('gpgme_op_')
-                 and not name.endswith('_result'))
-                or name in {
-                    'gpgme_new',
-                    'gpgme_set_ctx_flag',
-                    'gpgme_set_protocol',
-                    'gpgme_set_sub_protocol',
-                    'gpgme_set_keylist_mode',
-                    'gpgme_set_pinentry_mode',
-                    'gpgme_set_locale',
-                    'gpgme_ctx_set_engine_info',
-                    'gpgme_signers_add',
-                    'gpgme_sig_notation_add',
-                    'gpgme_set_sender',
-                    'gpgme_cancel',
-                    'gpgme_cancel_async',
-                    'gpgme_get_key',
-                })
+        # | grep -v _op_ | awk "/\(gpgme_ctx/ { printf (\"'%s',\\n\", \$2) } "
+        return ((name.startswith('gpgme_op_') and not
+            name.endswith('_result')) or name in {'gpgme_new',
+            'gpgme_set_ctx_flag', 'gpgme_set_protocol',
+            'gpgme_set_sub_protocol', 'gpgme_set_keylist_mode',
+            'gpgme_set_pinentry_mode', 'gpgme_set_locale',
+            'gpgme_ctx_set_engine_info', 'gpgme_signers_add',
+            'gpgme_sig_notation_add', 'gpgme_set_sender', 'gpgme_cancel',
+            'gpgme_cancel_async', 'gpgme_get_key'})
 
     _boolean_properties = {'armor', 'textmode', 'offline'}
 
@@ -985,6 +994,7 @@ class Context(GpgmeWrapper):
     # Implement the context manager protocol.
     def __enter__(self):
         return self
+
     def __exit__(self, type, value, tb):
         self.__del__()
 
@@ -1079,10 +1089,10 @@ class Context(GpgmeWrapper):
 
         Please see the GPGME manual for more information.
         """
-        if func == None:
+        if func is None:
             hookdata = None
         else:
-            if hook == None:
+            if hook is None:
                 hookdata = (weakref.ref(self), func)
             else:
                 hookdata = (weakref.ref(self), func, hook)
@@ -1104,10 +1114,10 @@ class Context(GpgmeWrapper):
         Please see the GPGME manual for more information.
 
         """
-        if func == None:
+        if func is None:
             hookdata = None
         else:
-            if hook == None:
+            if hook is None:
                 hookdata = (weakref.ref(self), func)
             else:
                 hookdata = (weakref.ref(self), func, hook)
@@ -1128,10 +1138,10 @@ class Context(GpgmeWrapper):
         Please see the GPGME manual for more information.
 
         """
-        if func == None:
+        if func is None:
             hookdata = None
         else:
-            if hook == None:
+            if hook is None:
                 hookdata = (weakref.ref(self), func)
             else:
                 hookdata = (weakref.ref(self), func, hook)
@@ -1229,7 +1239,8 @@ class Data(GpgmeWrapper):
         # This list is compiled using
         #
         # $ grep -v '^gpgme_error_t ' obj/lang/python/python3.5-gpg/gpgme.h \
-        #   | awk "/\(gpgme_data_t/ { printf (\"'%s',\\n\", \$2) } " | sed "s/'\\*/'/"
+        #   | awk "/\(gpgme_data_t/ { printf (\"'%s',\\n\", \$2) } " \
+        #   | sed "s/'\\*/'/"
         return name not in {
             'gpgme_data_read',
             'gpgme_data_write',
@@ -1286,13 +1297,13 @@ class Data(GpgmeWrapper):
         super(Data, self).__init__(None)
         self.data_cbs = None
 
-        if cbs != None:
+        if cbs is not None:
             self.new_from_cbs(*cbs)
-        elif string != None:
+        elif string is not None:
             self.new_from_mem(string, copy)
-        elif file != None and offset != None and length != None:
+        elif file is not None and offset is not None and length is not None:
             self.new_from_filepart(file, offset, length)
-        elif file != None:
+        elif file is not None:
             if util.is_a_string(file):
                 self.new_from_file(file, copy)
             else:
@@ -1305,7 +1316,7 @@ class Data(GpgmeWrapper):
             # At interpreter shutdown, gpgme is set to NONE.
             return
 
-        if self.wrapped != None and gpgme.gpgme_data_release:
+        if self.wrapped is not None and gpgme.gpgme_data_release:
             gpgme.gpgme_data_release(self.wrapped)
             if self._callback_excinfo:
                 gpgme.gpg_raise_callback_exception(self)
@@ -1315,6 +1326,7 @@ class Data(GpgmeWrapper):
     # Implement the context manager protocol.
     def __enter__(self):
         return self
+
     def __exit__(self, type, value, tb):
         self.__del__()
 
@@ -1329,7 +1341,8 @@ class Data(GpgmeWrapper):
 
     def new_from_mem(self, string, copy=True):
         tmp = gpgme.new_gpgme_data_t_p()
-        errorcheck(gpgme.gpgme_data_new_from_mem(tmp,string,len(string),copy))
+        errorcheck(gpgme.gpgme_data_new_from_mem(tmp, string, len(string),
+                                                 copy))
         self.wrapped = gpgme.gpgme_data_t_p_value(tmp)
         gpgme.delete_gpgme_data_t_p(tmp)
 
@@ -1347,7 +1360,7 @@ class Data(GpgmeWrapper):
 
     def new_from_cbs(self, read_cb, write_cb, seek_cb, release_cb, hook=None):
         tmp = gpgme.new_gpgme_data_t_p()
-        if hook != None:
+        if hook is not None:
             hookdata = (weakref.ref(self),
                         read_cb, write_cb, seek_cb, release_cb, hook)
         else:
@@ -1374,9 +1387,9 @@ class Data(GpgmeWrapper):
             filename = file
         else:
             fp = gpgme.fdopen(file.fileno(), file.mode)
-            if fp == None:
-                raise ValueError("Failed to open file from %s arg %s" % \
-                      (str(type(file)), str(file)))
+            if fp is None:
+                raise ValueError("Failed to open file from %s arg %s" %
+                                 (str(type(file)), str(file)))
 
         errorcheck(gpgme.gpgme_data_new_from_filepart(tmp, filename, fp,
                                                       offset, length))
@@ -1412,7 +1425,7 @@ class Data(GpgmeWrapper):
                 raise GPGMEError.fromSyserror()
         return written
 
-    def read(self, size = -1):
+    def read(self, size=-1):
         """Read at most size bytes, returned as bytes.
 
         If the size argument is negative or omitted, read until EOF is reached.
@@ -1447,6 +1460,7 @@ class Data(GpgmeWrapper):
                 chunks.append(result)
             return b''.join(chunks)
 
+
 def pubkey_algo_string(subkey):
     """Return short algorithm string
 
@@ -1459,6 +1473,7 @@ def pubkey_algo_string(subkey):
     """
     return gpgme.gpgme_pubkey_algo_string(subkey)
 
+
 def pubkey_algo_name(algo):
     """Return name of public key algorithm
 
@@ -1471,6 +1486,7 @@ def pubkey_algo_name(algo):
     """
     return gpgme.gpgme_pubkey_algo_name(algo)
 
+
 def hash_algo_name(algo):
     """Return name of hash algorithm
 
@@ -1483,6 +1499,7 @@ def hash_algo_name(algo):
     """
     return gpgme.gpgme_hash_algo_name(algo)
 
+
 def get_protocol_name(proto):
     """Get protocol description
 
@@ -1494,6 +1511,7 @@ def get_protocol_name(proto):
     """
     return gpgme.gpgme_get_protocol_name(proto)
 
+
 def addrspec_from_uid(uid):
     """Return the address spec
 
@@ -1505,6 +1523,7 @@ def addrspec_from_uid(uid):
     """
     return gpgme.gpgme_addrspec_from_uid(uid)
 
+
 def check_version(version=None):
     return gpgme.gpgme_check_version(version)
 
@@ -1514,13 +1533,15 @@ def check_version(version=None):
 # it unless she really wants to check for a certain version.
 check_version()
 
-def engine_check_version (proto):
+
+def engine_check_version(proto):
     try:
         errorcheck(gpgme.gpgme_engine_check_version(proto))
         return True
     except errors.GPGMEError:
         return False
 
+
 def get_engine_info():
     ptr = gpgme.new_gpgme_engine_info_t_p()
     try:
@@ -1531,6 +1552,7 @@ def get_engine_info():
     gpgme.delete_gpgme_engine_info_t_p(ptr)
     return info
 
+
 def set_engine_info(proto, file_name, home_dir=None):
     """Changes the default configuration of the crypto engine implementing
     the protocol 'proto'. 'file_name' is the file name of
@@ -1539,10 +1561,12 @@ def set_engine_info(proto, file_name, home_dir=None):
     used if omitted)."""
     errorcheck(gpgme.gpgme_set_engine_info(proto, file_name, home_dir))
 
+
 def set_locale(category, value):
     """Sets the default locale used by contexts"""
     errorcheck(gpgme.gpgme_set_locale(None, category, value))
 
+
 def wait(hang):
     """Wait for asynchronous call on any Context  to finish.
     Wait forever if hang is True.
@@ -1556,7 +1580,7 @@ def wait(hang):
     context = gpgme.gpgme_wait(None, ptr, hang)
     status = gpgme.gpgme_error_t_p_value(ptr)
     gpgme.delete_gpgme_error_t_p(ptr)
-    if context == None:
+    if context is None:
         errorcheck(status)
     else:
         context = Context(context)