cleanup old python compat -- removed suppress_cause() and error_from() wrappers

9 files changed, 18 insertions, 36 deletions

diff --git a/passlib/crypto/digest.py b/passlib/crypto/digest.py
index eb37e6f..4f7bc97 100644
--- a/passlib/crypto/digest.py
+++ b/passlib/crypto/digest.py
@@ -32,7 +32,7 @@ except ImportError:
 from passlib import exc
 from passlib.utils import join_bytes, to_native_str, join_byte_values, to_bytes, \
                           SequenceMixin, as_bool
-from passlib.utils.compat import int_types, unicode_or_bytes_types, error_from
+from passlib.utils.compat import int_types, unicode_or_bytes_types
 from passlib.utils.decor import memoized_property
 # local
 __all__ = [
diff --git a/passlib/handlers/bcrypt.py b/passlib/handlers/bcrypt.py
index dda7433..762b7ee 100644
--- a/passlib/handlers/bcrypt.py
+++ b/passlib/handlers/bcrypt.py
@@ -29,7 +29,7 @@ from passlib.utils import safe_crypt, repeat_string, to_bytes, parse_version, \
                           rng, getrandstr, test_crypt, to_unicode, \
                           utf8_truncate, utf8_repeat_string, crypt_accepts_bytes
 from passlib.utils.binary import bcrypt64
-from passlib.utils.compat import uascii_to_str, unicode, str_to_uascii, error_from
+from passlib.utils.compat import uascii_to_str, unicode, str_to_uascii
 import passlib.utils.handlers as uh
 
 # local
@@ -812,10 +812,10 @@ class _OsCryptBackend(_BcryptCommon):
             try:
                 secret.decode("utf-8")
             except UnicodeDecodeError:
-                raise error_from(uh.exc.PasswordValueError(
+                raise uh.exc.PasswordValueError(
                     "python3 crypt.crypt() ony supports bytes passwords using UTF8; "
                     "passlib recommends running `pip install bcrypt` for general bcrypt support.",
-                    ), None)
+                    ) from None
 
         #
         # else crypt() call failed for unknown reason.
diff --git a/passlib/handlers/des_crypt.py b/passlib/handlers/des_crypt.py
index 3c7bb7e..80a9ec2 100644
--- a/passlib/handlers/des_crypt.py
+++ b/passlib/handlers/des_crypt.py
@@ -10,7 +10,7 @@ from warnings import warn
 # pkg
 from passlib.utils import safe_crypt, test_crypt, to_unicode
 from passlib.utils.binary import h64, h64big
-from passlib.utils.compat import byte_elem_value, u, uascii_to_str, unicode, suppress_cause
+from passlib.utils.compat import byte_elem_value, u, uascii_to_str, unicode
 from passlib.crypto.des import des_encrypt_int_block
 import passlib.utils.handlers as uh
 # local
@@ -579,8 +579,8 @@ class crypt16(uh.TruncateMixin, uh.HasSalt, uh.GenericHandler):
         # parse salt value
         try:
             salt_value = h64.decode_int12(self.salt.encode("ascii"))
-        except ValueError: # pragma: no cover - caught by class
-            raise suppress_cause(ValueError("invalid chars in salt"))
+        except ValueError:  # pragma: no cover - caught by class
+            raise ValueError("invalid chars in salt") from None
 
         # convert first 8 byts of secret string into an integer,
         key1 = _crypt_secret_to_key(secret)
diff --git a/passlib/handlers/scrypt.py b/passlib/handlers/scrypt.py
index 57b921e..f3113dd 100644
--- a/passlib/handlers/scrypt.py
+++ b/passlib/handlers/scrypt.py
@@ -9,7 +9,7 @@ import logging; log = logging.getLogger(__name__)
 from passlib.crypto import scrypt as _scrypt
 from passlib.utils import h64, to_bytes
 from passlib.utils.binary import h64, b64s_decode, b64s_encode
-from passlib.utils.compat import bascii_to_str, suppress_cause
+from passlib.utils.compat import bascii_to_str
 from passlib.utils.decor import classproperty
 import passlib.utils.handlers as uh
 # local
@@ -163,7 +163,7 @@ class scrypt(uh.ParallelismMixin, uh.HasRounds, uh.HasRawSalt, uh.HasRawChecksum
         try:
             _scrypt.validate(1 << cls.default_rounds, cls.block_size, cls.parallelism)
         except ValueError as err:
-            raise suppress_cause(ValueError("scrypt: invalid settings combination: " + str(err)))
+            raise ValueError("scrypt: invalid settings combination: " + str(err)) from None
 
         return subcls
 
@@ -287,7 +287,7 @@ class scrypt(uh.ParallelismMixin, uh.HasRounds, uh.HasRawSalt, uh.HasRawChecksum
             try:
                 salt.decode("ascii")
             except UnicodeDecodeError:
-                raise suppress_cause(NotImplementedError("scrypt $7$ hashes dont support non-ascii salts"))
+                raise NotImplementedError("scrypt $7$ hashes dont support non-ascii salts") from None
             return bascii_to_str(b"".join([
                 b"$7$",
                 h64.encode_int6(self.rounds),
diff --git a/passlib/tests/test_ext_django_source.py b/passlib/tests/test_ext_django_source.py
index 49d66cb..cc8c25f 100644
--- a/passlib/tests/test_ext_django_source.py
+++ b/passlib/tests/test_ext_django_source.py
@@ -8,7 +8,6 @@ test passlib.ext.django against django source tests
 import logging; log = logging.getLogger(__name__)
 # site
 # pkg
-from passlib.utils.compat import suppress_cause
 from passlib.ext.django.utils import DJANGO_VERSION, DjangoTranslator, _PasslibHasherWrapper
 # tests
 from passlib.tests.utils import TestCase, TEST_MODE
@@ -59,10 +58,8 @@ elif has_min_django:
         try:
             from auth_tests import test_hashers as test_hashers_mod
         except ImportError as err:
-            raise suppress_cause(
-                EnvironmentError("error trying to import django tests "
-                                 "from source path (%r): %r" %
-                                 (source_path, err)))
+            raise  EnvironmentError("error trying to import django tests "
+                                    "from source path (%r): %r" % (source_path, err)) from None
         finally:
             sys.path.remove(tests_path)
 
diff --git a/passlib/totp.py b/passlib/totp.py
index 73605f2..b60284b 100644
--- a/passlib/totp.py
+++ b/passlib/totp.py
@@ -32,7 +32,7 @@ from passlib.utils import (to_unicode, to_bytes, consteq,
                            getrandbytes, rng, SequenceMixin, xor_bytes, getrandstr)
 from passlib.utils.binary import BASE64_CHARS, b32encode, b32decode
 from passlib.utils.compat import (u, unicode, native_string_types, bascii_to_str, int_types, num_types,
-                                  byte_elem_value, UnicodeIO, suppress_cause)
+                                  byte_elem_value, UnicodeIO)
 from passlib.utils.decor import hybrid_method, memoized_property
 from passlib.crypto.digest import lookup_hash, compile_hmac, pbkdf2_hmac
 from passlib.hash import pbkdf2_sha256
@@ -358,7 +358,7 @@ class AppWallet(object):
         try:
             return secrets[tag]
         except KeyError:
-            raise suppress_cause(KeyError("unknown secret tag: %r" % (tag,)))
+            raise KeyError("unknown secret tag: %r" % (tag,)) from None
 
     #========================================================================
     # encrypted key helpers -- used internally by TOTP
diff --git a/passlib/utils/__init__.py b/passlib/utils/__init__.py
index df4daf0..d6c61a0 100644
--- a/passlib/utils/__init__.py
+++ b/passlib/utils/__init__.py
@@ -65,7 +65,7 @@ from passlib.utils.compat import (add_doc, join_bytes, join_byte_values,
                                   join_byte_elems,
                                   join_unicode, unicode, byte_elem_value,
                                   unicode_or_str, unicode_or_bytes_types,
-                                  get_method_function, suppress_cause, PYPY)
+                                  get_method_function, PYPY)
 # local
 __all__ = [
     # constants
diff --git a/passlib/utils/binary.py b/passlib/utils/binary.py
index e5bdf2b..813d5cc 100644
--- a/passlib/utils/binary.py
+++ b/passlib/utils/binary.py
@@ -20,7 +20,6 @@ from passlib import exc
 from passlib.utils.compat import (
     bascii_to_str,
     iter_byte_chars, join_byte_values, join_byte_elems,
-    suppress_cause,
     unicode, unicode_or_bytes_types,
 )
 from passlib.utils.decor import memoized_property
@@ -156,7 +155,7 @@ def b64s_decode(data):
         try:
             data = data.encode("ascii")
         except UnicodeEncodeError:
-            raise suppress_cause(ValueError("string argument should contain only ASCII characters"))
+            raise ValueError("string argument should contain only ASCII characters") from None
     off = len(data) & 3
     if off == 0:
         pass
@@ -169,7 +168,7 @@ def b64s_decode(data):
     try:
         return a2b_base64(data)
     except _BinAsciiError as err:
-        raise suppress_cause(TypeError(err))
+        raise TypeError(err) from None
 
 #=============================================================================
 # adapted-base64 encoding
@@ -202,7 +201,7 @@ def ab64_decode(data):
         try:
             data = data.encode("ascii")
         except UnicodeEncodeError:
-            raise suppress_cause(ValueError("string argument should contain only ASCII characters"))
+            raise ValueError("string argument should contain only ASCII characters") from None
     return b64s_decode(data.replace(b".", b"+"))
 
 #=============================================================================
diff --git a/passlib/utils/compat/__init__.py b/passlib/utils/compat/__init__.py
index e582e0d..32cd777 100644
--- a/passlib/utils/compat/__init__.py
+++ b/passlib/utils/compat/__init__.py
@@ -178,20 +178,6 @@ def get_method_function(func):
     """given (potential) method, return underlying function"""
     return getattr(func, "__func__", func)
 
-def error_from(exc,  # *,
-               cause=None):
-    """
-    backward compat hack to suppress exception cause in python3.3+
-
-    one python < 3.3 support is dropped, can replace all uses with "raise exc from None"
-    """
-    exc.__cause__ = cause
-    exc.__suppress_context__ = True
-    return exc
-
-# legacy alias
-suppress_cause = error_from
-
 #=============================================================================
 # input/output
 #=============================================================================