Remove Python 2 compatibility helpers: to_bytes, to_native, to_unicode

Replace all call sites with direct .encode()/.decode() calls, as these
functions are trivial wrappers on Python 3.

Closes #197

Author: lavr

emails/loader/__init__.py

@@ -3,7 +3,6 @@
 
 import urllib.parse as urlparse
 
-from ..utils import to_unicode, to_native
 from ..message import Message
 from ..utils import fetch_url
 from .local_store import (FileSystemLoader, ZipLoader, MsgLoader, FileNotFound)
@@ -77,7 +76,7 @@ def _extract_base_url(url):
     # Load html page
     r = fetch_url(url, requests_args=requests_params)
     html = r.content
-    html = to_unicode(html, charset=guess_charset(r.headers, html))
+    html = html.decode(guess_charset(r.headers, html) or 'utf-8')
     html = html.replace('\r\n', '\n')  # Remove \r
 
     return from_html(html,

emails/loader/helpers.py

@@ -12,7 +12,6 @@
 except ImportError:
     import chardet
 
-from ..utils import to_native, to_unicode
 
 # HTML page charset stuff
 
@@ -29,7 +28,7 @@ def __init__(self, conv=None):
             if k.startswith('re_'):
                 setattr(self, k, re.compile(conv(getattr(self, k)), re.I + re.S + re.M))
 
-RULES_U = ReRules(conv=to_unicode)
+RULES_U = ReRules(conv=lambda x: x.decode())
 RULES_B = ReRules()
 
 
@@ -40,13 +39,13 @@ def guess_text_charset(text, is_html=False):
             if rules.re_is_http_equiv.findall(meta):
                 for content in rules.re_parse_http_equiv.findall(meta):
                     for charset in rules.re_charset.findall(content):
-                        return to_native(charset)
+                        return charset.decode() if isinstance(charset, bytes) else charset
             else:
                 for charset in rules.re_charset.findall(meta):
-                    return to_native(charset)
+                    return charset.decode() if isinstance(charset, bytes) else charset
     # guess by chardet
     if isinstance(text, bytes):
-        return to_native(chardet.detect(text)['encoding'])
+        return chardet.detect(text)['encoding']
 
 
 def guess_html_charset(html):
@@ -68,7 +67,7 @@ def guess_charset(headers, html):
     # guess by html content
     charset = guess_html_charset(html)
     if charset:
-        return to_unicode(charset)
+        return charset
 
 COMMON_CHARSETS = ('ascii', 'utf-8', 'utf-16', 'windows-1251', 'windows-1252', 'cp850')
 
@@ -100,7 +99,7 @@ def decode_text(text,
     _last_exc = None
     for enc in _charsets:
         try:
-            return to_unicode(text, charset=enc), enc
+            return text.decode(enc), enc
         except UnicodeDecodeError as exc:
             _last_exc = exc
 

emails/loader/local_store.py

@@ -8,7 +8,7 @@
 from zipfile import ZipFile
 import email
 
-from ..utils import to_unicode, to_native, formataddr, decode_header
+from ..utils import formataddr, decode_header
 from ..loader.helpers import decode_text
 from ..message import Message
 
@@ -183,7 +183,7 @@ def __init__(self, file, encoding='utf-8', base_path=None):
     def _decode_filename(self, name):
         for enc in self.common_filename_charsets:
             try:
-                return to_unicode(name, enc)
+                return name.decode(enc) if isinstance(name, bytes) else name
             except UnicodeDecodeError:
                 pass
         return name
@@ -203,7 +203,7 @@ def get_file(self, name):
         self._unpack()
 
         if isinstance(name, str):
-            name = to_unicode(name, 'utf-8')
+            name = name.decode('utf-8') if isinstance(name, bytes) else name
 
         if name not in self._original_filenames:
             name = self._decoded_filenames.get(name)
@@ -229,7 +229,7 @@ def __init__(self, msg, base_path=None):
         if isinstance(msg, str):
             self.msg = email.message_from_string(msg)
         elif isinstance(msg, bytes):
-            self.msg = email.message_from_string(to_native(msg))
+            self.msg = email.message_from_string(msg.decode())
         else:
             self.msg = msg
         self.base_path = base_path

emails/store/file.py

@@ -9,7 +9,7 @@
 
 import urllib.parse as urlparse
 
-from ..utils import fetch_url, encode_header, to_bytes
+from ..utils import fetch_url, encode_header
 
 
 MIMETYPE_UNKNOWN = 'application/unknown'
@@ -143,7 +143,12 @@ def mime(self) -> MIMEBase | None:
         if p is None:
             filename_header = encode_header(self.filename)
             p = MIMEBase(*self.mime_type.split('/', 1), name=filename_header)
-            payload = to_bytes(self.data) or b''
+            if isinstance(self.data, str):
+                payload = self.data.encode()
+            elif self.data is not None:
+                payload = bytes(self.data)
+            else:
+                payload = b''
             p.set_payload(payload)
             encode_base64(p)
             if 'content-disposition' not in self._headers:

emails/testsuite/loader/test_rfc822_loader.py

@@ -2,7 +2,6 @@
 import email
 import datetime
 import os.path
-from emails.utils import to_native
 import emails.loader
 from emails.loader.local_store import MsgLoader
 
@@ -79,7 +78,7 @@ def test_msgloader():
 def _try_decode(s, charsets=('utf-8', 'koi8-r', 'cp1251')):
     for charset in charsets:
         try:
-            return to_native(s, charset), charset
+            return s.decode(charset), charset
         except UnicodeDecodeError:
             pass
     return None, None

emails/testsuite/message/test_dkim.py

@@ -5,7 +5,6 @@
 from emails import Message
 from io import StringIO
 
-from emails.utils import to_bytes, to_native
 from emails.exc import DKIMException
 from emails.utils import load_email_charsets
 import emails.packages.dkim
@@ -40,7 +39,7 @@ def _generate_key(length=1024):
     try:
         from Crypto.PublicKey import RSA
         key = RSA.generate(length)
-        return to_bytes(key.exportKey()), to_bytes(key.publickey().exportKey())
+        return key.exportKey(), key.publickey().exportKey()
     except ImportError:
         return PRIV_KEY, PUB_KEY
 
@@ -49,15 +48,15 @@ def _check_dkim(message, pub_key=PUB_KEY):
     def _plain_public_key(s):
         return b"".join([l for l in s.split(b'\n') if not l.startswith(b'---')])
     message = message.as_string()
-    o = emails.packages.dkim.DKIM(message=to_bytes(message))
+    o = emails.packages.dkim.DKIM(message=message.encode())
     return o.verify(dnsfunc=lambda name: b"".join([b"v=DKIM1; p=", _plain_public_key(pub_key)]))
 
 
 def test_dkim():
 
     priv_key, pub_key = _generate_key(length=1024)
 
-    DKIM_PARAMS = [dict(key=StringIO(to_native(priv_key)),
+    DKIM_PARAMS = [dict(key=StringIO(priv_key.decode()),
                         selector='_dkim',
                         domain='somewhere1.net'),
 
@@ -150,7 +149,7 @@ def test_dkim_sign_twice():
 
     priv_key, pub_key = _generate_key(length=1024)
     message = Message(**common_email_data())
-    message.dkim(key=StringIO(to_native(priv_key)), selector='_dkim', domain='somewhere.net')
+    message.dkim(key=StringIO(priv_key.decode()), selector='_dkim', domain='somewhere.net')
     for n in range(2):
         message.subject = 'Test %s' % n
         assert _check_dkim(message, pub_key)

emails/testsuite/message/test_message.py

@@ -8,7 +8,6 @@
 import emails.exc
 from io import StringIO
 
-from emails.utils import to_unicode
 from emails.utils import decode_header, MessageID
 from emails.backend.inmemory import InMemoryBackend
 
@@ -73,7 +72,7 @@ def my_after_build(original_message, built_message):
 
     s = m.as_string()
     print("type of message.as_string() is {0}".format(type(s)))
-    assert AFTER_BUILD_HEADER in to_unicode(s, 'utf-8')
+    assert AFTER_BUILD_HEADER in s
 
 
 def test_before_build():

emails/testsuite/smtp_servers.py

@@ -3,7 +3,6 @@
 import datetime
 import random
 import time
-from emails.utils import to_unicode
 
 DEFAULT_FROM = os.environ.get('SMTP_TEST_FROM_EMAIL') or 'python-emails@lavr.me'
 SUBJECT_SUFFIX = os.environ.get('SMTP_TEST_SUBJECT_SUFFIX')
@@ -88,7 +87,7 @@ def patch_message(self, message):
             message.mail_to = self.to_email
 
         # TODO: this code breaks template in subject; fix it
-        if not to_unicode(message.subject).startswith(self.subject_prefix) :
+        if not message.subject.startswith(self.subject_prefix) :
             message.subject = " ".join([self.subject_prefix, message.subject,
                                         '// %s' % SUBJECT_SUFFIX])
 

emails/transformer.py

@@ -12,7 +12,6 @@
 
 import urllib.parse as urlparse
 
-from .utils import to_unicode
 from .loader.local_store import FileNotFound
 from .store import MemoryFileStore, LazyHTTPFile
 from .template.base import BaseTemplate
@@ -125,7 +124,8 @@ def _apply_to_style_uri(style_text, func):
                             dirty = True
                             value.uri = new_uri
             if dirty:
-                return to_unicode(parser.cssText, 'utf-8')
+                css_text = parser.cssText
+                return css_text.decode('utf-8') if isinstance(css_text, bytes) else css_text
             else:
                 return style_text
 

emails/utils.py

@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import sys
 import os
 import socket
 from time import mktime
@@ -9,7 +8,7 @@
 from functools import wraps
 from io import StringIO, BytesIO
 from collections.abc import Callable
-from typing import Any, TypeVar, cast, overload
+from typing import Any, TypeVar, cast
 
 import email.charset
 from email import generator
@@ -25,41 +24,6 @@
 F = TypeVar('F', bound=Callable[..., Any])
 
 
-def to_native(x: str | bytes | None, charset: str = sys.getdefaultencoding(),
-              errors: str = 'strict') -> str | None:
-    if x is None or isinstance(x, str):
-        return x
-    return x.decode(charset, errors)
-
-
-@overload
-def to_unicode(x: None, charset: str = ..., errors: str = ...) -> None: ...
-@overload
-def to_unicode(x: str | bytes, charset: str = ..., errors: str = ...) -> str: ...
-@overload
-def to_unicode(x: Any, charset: str = ..., errors: str = ...) -> str | None: ...
-
-def to_unicode(x: Any, charset: str = sys.getdefaultencoding(),
-               errors: str = 'strict') -> str | None:
-    if x is None:
-        return None
-    if not isinstance(x, bytes):
-        return str(x)
-    return x.decode(charset, errors)
-
-
-def to_bytes(x: str | bytes | bytearray | memoryview | None,
-             charset: str = sys.getdefaultencoding(),
-             errors: str = 'strict') -> bytes | None:
-    if x is None:
-        return None
-    if isinstance(x, (bytes, bytearray, memoryview)):
-        return bytes(x)
-    if isinstance(x, str):
-        return x.encode(charset, errors)
-    raise TypeError('Expected bytes')
-
-
 def formataddr(pair: tuple[str | None, str]) -> str:
     """
     Takes a 2-tuple of the form (realname, email_address) and returns RFC2822-like string.