在过时文件上执行行匹配的Python脚本会生成不一致的输出

Question

我创建了一个python脚本来解析邮件(exim)日志文件并执行模式匹配，以便在我的smtp服务器上获得大多数发送域的前100个列表。但是，每次执行脚本时，我都会得到不同的计数。这些都是过时的日志文件，我无法在我的代码中找到功能缺陷。

Example output:
    1:
    70353 gmail.com
    68337 hotmail.com
    53657 yahoo.com
    2:
    70020 gmail.com
    67741 hotmail.com
    54397 yahoo.com
    3:
    70191 gmail.com
    67917 hotmail.com
    54438 yahoo.com
Code:
#!/usr/bin/env python
import os
import datetime
import re
from collections import defaultdict
class DomainCounter(object):
def __init__(self):
    self.base_path = '/opt/mail_log'
    self.tmp = []
    self.date = datetime.date.today() - datetime.timedelta(days=14)
    self.file_out = '/var/tmp/parsed_exim_files-'  + str(self.date.strftime('%Y%m%d')) + '.decompressed'
def parse_log_files(self):
    sub_dir = os.listdir(self.base_path)
    for directory in sub_dir:
        if re.search('smtpd+', directory):
            fileInput = self.base_path + '/' + directory + '/maillog-' + str(self.date.strftime('%Y%m%d')) + '.bz2'
            if not os.path.isfile(self.file_out):
                 os.popen('touch ' + self.file_out)
            proccessFiles = os.popen('/bin/bunzip2 -cd ' + fileInput + ' > ' + self.file_out)
            accessFileHandle =  open(self.file_out, 'r')
            readFileHandle = accessFileHandle.readlines()
            print "Proccessing %s." % fileInput
            for line in readFileHandle:
                if '<=' in line and ' for ' in line and '<>' not in line:
                    distinctLine = line.split(' for ')
                    recipientAddresses = distinctLine[1].strip()
                    recipientAddressList = recipientAddresses.strip().split(' ')
                    if len(recipientAddressList) > 1:
                        for emailaddress in recipientAddressList:
                            # Since syslog messages are transmitted over UDP some messages are dropped and needs to be filtered out.
                            if '@' in emailaddress:
                                (login, domein) = emailaddress.split("@")
                                self.tmp.append(domein)
                                continue
    else:
        try:
                                (login, domein) = recipientAddressList[0].split("@")
                                self.tmp.append(domein)
        except Exception as e:
             print e, '<<No valid email address found, skipping line>>'
    accessFileHandle.close()
    os.unlink(self.file_out)
return self.tmp

if __name__ == '__main__':
domainCounter = DomainCounter()
result = domainCounter.parse_log_files()
domainCounts = defaultdict(int)
top = 100
for domain in result:
    domainCounts[domain] += 1
sortedDict = dict(sorted(domainCounts.items(), key=lambda x: x[1], reverse=True)[:int(top)])
for w in sorted(sortedDict, key=sortedDict.get, reverse=True):
    print '%-3s %s' % (sortedDict[w], w)

Answer 1

proccessFiles = os.popen('/bin/bunzip2 -cd ' + fileInput + ' > ' + self.file_out)

此行不阻塞。因此，它将启动命令，但是下面的几行已经在读取文件了。这基本上是一个并发问题。请尝试等待命令完成后再读取文件。

也看到:Python popen命令。等待命令完成，因为os.popen自python-2.6以来已弃用(取决于您使用的是哪个版本)。

旁注-下面一行也是如此。执行以下行后，文件可能存在，也可能不存在:

os.popen('touch ' + self.file_out)