bpo-35128: Fix spacing issues in warning.warn() messages. (GH-10268)

diff --git a/Lib/bz2.py b/Lib/bz2.py
index 3ab0991..21e8ff4 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -66,7 +66,7 @@
         self._mode = _MODE_CLOSED
 
         if buffering is not _sentinel:
-            warnings.warn("Use of 'buffering' argument is deprecated  and ignored"
+            warnings.warn("Use of 'buffering' argument is deprecated and ignored "
                           "since Python 3.0.",
                           DeprecationWarning,
                           stacklevel=2)
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index 05840d4..9611282 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -732,7 +732,7 @@
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile
diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index e451413..dd237f7 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -1277,7 +1277,7 @@
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom ssl_context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile
diff --git a/Lib/poplib.py b/Lib/poplib.py
index d8a62c0..9796f0d 100644
--- a/Lib/poplib.py
+++ b/Lib/poplib.py
@@ -436,7 +436,7 @@
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile
diff --git a/Lib/smtplib.py b/Lib/smtplib.py
index acfc358..3c5ac75 100755
--- a/Lib/smtplib.py
+++ b/Lib/smtplib.py
@@ -764,7 +764,7 @@
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             if context is None:
                 context = ssl._create_stdlib_context(certfile=certfile,
@@ -1021,7 +1021,7 @@
                                  "exclusive")
             if keyfile is not None or certfile is not None:
                 import warnings
-                warnings.warn("keyfile and certfile are deprecated, use a"
+                warnings.warn("keyfile and certfile are deprecated, use a "
                               "custom context instead", DeprecationWarning, 2)
             self.keyfile = keyfile
             self.certfile = certfile