bayes/add_message

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#!/usr/bin/python3
import argparse
import email.parser
import email.policy
import os
import psycopg2
import psycopg2.extras as ppe
components = {}
def add_component(t, c):
if t not in components:
components[t] = []
components[t].append(c)
def add_message(msg):
for h in msg.items():
add_component(*h)
if msg.is_multipart():
for p in msg.get_payload():
add_message(p)
else:
if msg.get_content_maintype() == "text":
charset = msg.get_param("charset", "iso-8859-1")
add_component(
msg.get_content_subtype(),
msg.get_payload(decode=True)
.decode(charset, errors='replace'))
def extract_features(msgtype, msgid):
db = psycopg2.connect("dbname=bayes")
csr = db.cursor(cursor_factory=ppe.DictCursor)
csr.execute(
"""
insert into messages(id, type, message_id)
values(default, %s, %s)
returning id
""",
(msgtype, msgid))
msg_pk = csr.fetchone()["id"]
for t in components:
prev = {""}
length = 1
while prev:
current = set()
for c in components[t]:
for o in range(0, len(c) - length + 1):
f = c[o:o+length]
fp = f[:-1]
if fp in prev:
current.add(f)
# Record for this message
for f in current:
csr.execute(
"insert into message_features(message, type, length, feature) values(%s, %s, %s, %s)",
(msg_pk, t, length, f))
db.commit()
# We keep only those as "prev" values which already existed
# in the database
prev = set()
if current:
q = "select * from features where type = %s and length = %s and feature in (" + ", ".join(("%s",) * len(current)) + ")"
csr.execute(q, (t, length, *current))
for r in csr:
prev.add(r["feature"])
length += 1
def main():
ap = argparse.ArgumentParser()
ap.add_argument('file', nargs='?')
ap.add_argument('--spam', action="store_const", const="spam", dest="type")
ap.add_argument('--ham', action="store_const", const="ham", dest="type")
args = ap.parse_args()
if args.file:
fh = open(args.file, "rb")
else:
fh = os.fdopen(0, "rb")
parser = email.parser.BytesParser(policy=email.policy.default)
msg = parser.parse(fh)
add_message(msg)
extract_features(args.type, msg["Message-Id"])
main()