Modified help_text and added exception when number of participants is odd

secret_santa.py

@@ -0,0 +1,192 @@
+import yaml
+# sudo pip install pyyaml
+import re
+import random
+import smtplib
+import datetime
+import pytz
+import time
+import socket
+import sys
+import getopt
+import os
+
+help_message = '''
+To use, fill out config.yml with your own participants. You can also specify 
+couples so that people don't get assigned their significant other.
+
+You'll also need to specify your mail server settings. An example is provided
+for routing mail through gmail.
+
+For more information, see README.
+'''
+
+REQRD = (
+    'SMTP_SERVER', 
+    'SMTP_PORT', 
+    'USERNAME', 
+    'PASSWORD', 
+    'TIMEZONE', 
+    'PARTICIPANTS', 
+    'COUPLES', 
+    'FROM', 
+    'SUBJECT', 
+    'MESSAGE',
+)
+
+HEADER = """Date: {date}
+Content-Type: text/plain; charset="utf-8"
+Message-Id: {message_id}
+From: {frm}
+To: {to}
+Subject: {subject}
+        
+"""
+
+CONFIG_PATH = os.path.join(os.path.dirname(__file__), 'config.yml')
+
+class Person:
+    def __init__(self, name, email, partner):
+        self.name = name
+        self.email = email
+        self.partner = partner
+    
+    def __str__(self):
+        return "%s <%s>" % (self.name, self.email)
+
+class Pair:
+    def __init__(self, giver, reciever):
+        self.giver = giver
+        self.reciever = reciever
+    
+    def __str__(self):
+        return "%s ---> %s" % (self.giver.name, self.reciever.name)
+
+def parse_yaml(yaml_path=CONFIG_PATH):
+    return yaml.load(open(yaml_path))    
+
+def choose_reciever(giver, recievers):
+    choice = random.choice(recievers)
+    if giver.partner == choice.name or giver.name == choice.name:
+        if len(recievers) is 1:
+            raise Exception('Only one reciever left, try again')
+        return choose_reciever(giver, recievers)
+    else:
+        return choice
+
+def create_pairs(g, r):
+    givers = g[:]
+    recievers = r[:]
+    pairs = []
+    for giver in givers:
+        try:
+            reciever = choose_reciever(giver, recievers)
+            recievers.remove(reciever)
+            pairs.append(Pair(giver, reciever))
+        except:
+            return create_pairs(g, r)
+    return pairs
+
+
+class Usage(Exception):
+    def __init__(self, msg):
+        self.msg = msg
+
+
+def main(argv=None):
+    if argv is None:
+        argv = sys.argv
+    try:
+        try:
+            opts, args = getopt.getopt(argv[1:], "shc", ["send", "help"])
+        except getopt.error, msg:
+            raise Usage(msg)
+    
+        # option processing
+        send = False
+        for option, value in opts:
+            if option in ("-s", "--send"):
+                send = True
+            if option in ("-h", "--help"):
+                raise Usage(help_message)
+                
+        config = parse_yaml()
+        for key in REQRD:
+            if key not in config.keys():
+                raise Exception(
+                    'Required parameter %s not in yaml config file!' % (key,))
+
+        participants = config['PARTICIPANTS']
+        couples = config['COUPLES']
+        if len(participants) < 2:
+            raise Exception('Not enough participants specified.')
+        
+        if len(participants) % 2:
+            raise Exception('Uneven number of participants!')
+        
+        givers = []
+        for person in participants:
+            name, email = re.match(r'([^<]*)<([^>]*)>', person).groups()
+            name = name.strip()
+            partner = None
+            for couple in couples:
+                names = [n.strip() for n in couple.split(',')]
+                if name in names:
+                    # is part of this couple
+                    for member in names:
+                        if name != member:
+                            partner = member
+            person = Person(name, email, partner)
+            givers.append(person)
+        
+        recievers = givers[:]
+        pairs = create_pairs(givers, recievers)
+        if not send:
+            print """
+Test pairings:
+                
+%s
+                
+To send out emails with new pairings,
+call with the --send argument:
+
+    $ python secret_santa.py --send
+            
+            """ % ("\n".join([str(p) for p in pairs]))
+        
+        if send:
+            server = smtplib.SMTP(config['SMTP_SERVER'], config['SMTP_PORT'])
+            server.starttls()
+            server.login(config['USERNAME'], config['PASSWORD'])
+        for pair in pairs:
+            zone = pytz.timezone(config['TIMEZONE'])
+            now = zone.localize(datetime.datetime.now())
+            date = now.strftime('%a, %d %b %Y %T %Z') # Sun, 21 Dec 2008 06:25:23 +0000
+            message_id = '<%s@%s>' % (str(time.time())+str(random.random()), socket.gethostname())
+            frm = config['FROM']
+            to = pair.giver.email
+            subject = config['SUBJECT'].format(santa=pair.giver.name, santee=pair.reciever.name)
+            body = (HEADER+config['MESSAGE']).format(
+                date=date, 
+                message_id=message_id, 
+                frm=frm, 
+                to=to, 
+                subject=subject,
+                santa=pair.giver.name,
+                santee=pair.reciever.name,
+            )
+            if send:
+                result = server.sendmail(frm, [to], body)
+                print "Emailed %s <%s>" % (pair.giver.name, to)
+
+        if send:
+            server.quit()
+        
+    except Usage, err:
+        print >> sys.stderr, sys.argv[0].split("/")[-1] + ": " + str(err.msg)
+        print >> sys.stderr, "\t for help use --help"
+        return 2
+
+
+if __name__ == "__main__":
+    sys.exit(main())