refactor: passage argparse

mailing.py

@@ -22,27 +22,44 @@
 # This program is used to mail a message to several recipients, thus
 # providing customization for each recipient.
 
-import sys, getopt, re
+import argparse, sys, re
 import smtplib, time, mimetypes
 from email.header import Header
 from email.message import EmailMessage
 
-#
-# displays usage of the program, then quit
-#
-def usage(returncode):
-    print(
-        """SYNTAX:
-    """,
-        sys.argv[0],
-        """ -t tofile -b bodyfile [-p attachedfile]
 
-    tofile   : sort of CSV file containing addresses of recipients
-    bodyfile : template of the mail to be sent
-    attachedfile : optionnal attachment
-    """,
+parser = argparse.ArgumentParser(
+    description="""
+Simple mailing script.
+"""
+)
+
+ma = parser.add_argument_group(title="mandatory arguments", description=None)
+ma.add_argument(
+    "-t",
+    "--tofile",
+    metavar="TO.FILE",
+    type=str,
+    required=True,
+    help="Sort of CSV file containing addresses of recipients.",
+)
+ma.add_argument(
+    "-b",
+    "--bodyfile",
+    metavar="BODY.FILE",
+    type=str,
+    required=True,
+    help="Template of the mail to be sent",
+)
+
+parser.add_argument(
+    "-a",
+    "--attachement",
+    metavar="ATTACHED.FILE",
+    type=str,
+    nargs="?",
+    help="Optionnal attachment.",
 )
-    sys.exit(returncode)
 
 
 TOFILE = None
@@ -180,26 +197,10 @@ def send_message(message, to, attachment):
 
 if __name__ == "__main__":
 
-    # handle options of the program
-    try:
-        opts, args = getopt.getopt(sys.argv[1:], "t:b:p:")
-    except getopt.error as msg:
-        print("getopt error: %s" % msg)
-        usage(1)
-
-    for name, value in opts:
-        if name == "-t":
-            TOFILE = value
-        elif name == "-b":
-            BODYFILE = value
-        elif name == "-p":
-            JOINFILE = value
-        else:
-            print("argument: ", name, " invalid")
-            usage(1)
-
-    if not TOFILE or not BODYFILE:
-        usage(1)
+    args = parser.parse_args()
+    TOFILE = args.tofile
+    BODYFILE = args.bodyfile
+    JOINFILE = args.attachement
 
     # read the recipients file
     sets = read_recipients()