hauntsaninja · Oct 12, 2023 · Sep 25, 2023 · Sep 25, 2023 · Sep 25, 2023 · Sep 25, 2023
diff --git a/Lib/email/_msgid.py b/Lib/email/_msgid.py
@@ -0,0 +1,29 @@
+# This function used to be part of email.utils,
+# but has been separated out to speedup the import of that module
+
+import os
+import random
+import socket
+import time
+
+def make_msgid(idstring=None, domain=None):
+    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
+
+    <142480216486.20800.16526388040877946887@nightshade.la.mastaler.com>
+
+    Optional idstring if given is a string used to strengthen the
+    uniqueness of the message id.  Optional domain if given provides the
+    portion of the message id after the '@'.  It defaults to the locally
+    defined hostname.
+    """
+    timeval = int(time.time()*100)
+    pid = os.getpid()
+    randint = random.getrandbits(64)
+    if idstring is None:
+        idstring = ''
+    else:
+        idstring = '.' + idstring
+    if domain is None:
+        domain = socket.getfqdn()
+    msgid = '<%d.%d.%d%s@%s>' % (timeval, pid, randint, idstring, domain)
+    return msgid
@@ -22,11 +22,8 @@
     'unquote',
     ]
 
-import os
 import re
 import time
-import random
-import socket
 import datetime
 import urllib.parse
 
@@ -36,9 +33,6 @@
 
 from email._parseaddr import parsedate, parsedate_tz, _parsedate_tz
 
-# Intrapackage imports
-from email.charset import Charset
-
 COMMASPACE = ', '
 EMPTYSTRING = ''
 UEMPTYSTRING = ''
@@ -94,6 +88,8 @@ def formataddr(pair, charset='utf-8'):
             name.encode('ascii')
         except UnicodeEncodeError:
             if isinstance(charset, str):
+                # lazy import to improve module import time
+                from email.charset import Charset
 # Some convenience routines.  Don't import Parser and Message as side-effects 
 # of importing email since those cascadingly import most of the rest of the 
 # email package. 
 def message_from_string(s, *args, **kws): 
     """Parse a string into a Message object model. 
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import Parser 
     return Parser(*args, **kws).parsestr(s) 
 def message_from_bytes(s, *args, **kws): 
     """Parse a bytes string into a Message object model. 
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import BytesParser 
     return BytesParser(*args, **kws).parsebytes(s) 
 def message_from_file(fp, *args, **kws): 
     """Read a file and parse its contents into a Message object model. 
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import Parser 
     return Parser(*args, **kws).parse(fp) 
 def message_from_binary_file(fp, *args, **kws): 
     """Read a binary file and parse its contents into a Message object model. 
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import BytesParser 
     return BytesParser(*args, **kws).parse(fp) 
 # Some convenience routines.  Don't import Parser and Message as side-effects 
 # of importing email since those cascadingly import most of the rest of the 
 # email package. 
 def message_from_string(s, *args, **kws): 
     """Parse a string into a Message object model. 
  
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import Parser 
     return Parser(*args, **kws).parsestr(s) 
  
 def message_from_bytes(s, *args, **kws): 
     """Parse a bytes string into a Message object model. 
  
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import BytesParser 
     return BytesParser(*args, **kws).parsebytes(s) 
  
 def message_from_file(fp, *args, **kws): 
     """Read a file and parse its contents into a Message object model. 
  
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import Parser 
     return Parser(*args, **kws).parse(fp) 
  
 def message_from_binary_file(fp, *args, **kws): 
     """Read a binary file and parse its contents into a Message object model. 
  
     Optional _class and strict are passed to the Parser constructor. 
     """ 
     from email.parser import BytesParser 
     return BytesParser(*args, **kws).parse(fp) 
                 charset = Charset(charset)
             encoded_name = charset.header_encode(name)
             return "%s <%s>" % (encoded_name, address)
@@ -171,29 +167,6 @@ def format_datetime(dt, usegmt=False):
     return _format_timetuple_and_zone(now, zone)
 
 
-def make_msgid(idstring=None, domain=None):
-    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
-
-    <142480216486.20800.16526388040877946887@nightshade.la.mastaler.com>
-
-    Optional idstring if given is a string used to strengthen the
-    uniqueness of the message id.  Optional domain if given provides the
-    portion of the message id after the '@'.  It defaults to the locally
-    defined hostname.
-    """
-    timeval = int(time.time()*100)
-    pid = os.getpid()
-    randint = random.getrandbits(64)
-    if idstring is None:
-        idstring = ''
-    else:
-        idstring = '.' + idstring
-    if domain is None:
-        domain = socket.getfqdn()
-    msgid = '<%d.%d.%d%s@%s>' % (timeval, pid, randint, idstring, domain)
-    return msgid
-
-
 def parsedate_to_datetime(data):
     parsed_date_tz = _parsedate_tz(data)
     if parsed_date_tz is None:
@@ -351,3 +324,11 @@ def localtime(dt=None, isdst=None):
     if dt is None:
         dt = datetime.datetime.now()
     return dt.astimezone()
+
+
+def __getattr__(attr):
+    # lazy import, to speedup module import time
+    if attr == "make_msgid":
+        from ._msgid import make_msgid
+        return make_msgid
+    raise AttributeError(f"module {__name__!r} has no attribute {attr!r}")
diff --git a/Misc/NEWS.d/next/Library/2023-09-25-10-47-22.gh-issue-109653.TUHrId.rst b/Misc/NEWS.d/next/Library/2023-09-25-10-47-22.gh-issue-109653.TUHrId.rst
@@ -0,0 +1,4 @@
+Reduce the import time of :mod:`email.utils` by around 46%. This results in
+the import time of :mod:`email.message` falling by around 28%, which in turn
+reduces the import time of :mod:`importlib.metadata` by around 5%. Patch by
+Alex Waygood.