File read and parse in python

parser.py

import datetime
from collections import defaultdict

lines = open("sampledata", 'r').read().split("\n")

data = []
for line in lines:
    try:
        ip, dt = line.split(" ")
    except:
        print(line)
    attime = datetime.datetime.strptime(dt, "%d/%b/%Y:%H:%M:%S")
    data.append((ip, attime))

print("Total records", len(data))

per_minute_cluster = defaultdict(list)
for d in data:
    per_minute_cluster[d[1].strftime("%d/%m/%Y:%H:%M")].append(d)
print("Per minute cluster:", len(per_minute_cluster))
print(per_minute_cluster.keys())

per_minute_count = [(k, len(v)) for k, v in per_minute_cluster.items()]
print("Per minute count:", len(per_minute_count))

per_min_count_avg = sum([i[1] for i in per_minute_count]) / float(len(per_minute_count))
print("Per min average: %s" % per_min_count_avg)

offenders = [(i[0], i[1]) for i in per_minute_count if i[1] > per_min_count_avg * 4.2]
print("\n".join(["%s %s" % i for i in offenders]))