Note Python 3.3 or higher required for generating dovecot and znc hashes

Also makes code slightly terser.

README.textile

@@ -140,9 +140,9 @@ Retype new password: foo
 
 Remove @{SHA512-CRYPT}@ and insert the rest as the @password_hash@ value.
 
-Alternatively, if you don't already have @doveadm@ installed, Python will generate the appropriate string for you (assuming your password is @password@):
+Alternatively, if you don't already have @doveadm@ installed, Python 3.3 or higher will generate the appropriate string for you on Unix-based platforms (assuming your password is @password@):
 
-bc. python3 -c 'import crypt; print(crypt.crypt("password"))'
+bc. python3 -c 'import crypt; print(crypt.crypt("password", salt=crypt.METHOD_SHA512))'
 
 Same for the IRC password hash...
 
@@ -154,9 +154,9 @@ bc. # znc --makepass
 
 Take the string beginning with @sha256#@ and insert it as the value for @irc_password_hash@.
 
-Alternatively, if you don't already have @znc@ installed, Python will generate the appropriate string for you:
+Alternatively, if you don't already have @znc@ installed, Python 3.3 or higher will generate the appropriate string for you on Unix-based platforms (assuming your password is @password@):
 
-bc. python3 -c 'import crypt; salt, hash = crypt.crypt("password", crypt.mksalt(crypt.METHOD_SHA256)).split("$")[2:]; print("sha256#{}#{}".format(hash, salt))'
+bc. python3 -c 'import crypt; print("sha256#{}#{}".format(*crypt.crypt("password", salt=crypt.METHOD_SHA256).split("$")[2:]))'
 
 For git hosting, copy your public key into place. @cp ~/.ssh/id_rsa.pub roles/git/files/gitolite.pub@ or similar.