Question

在here的帮助下，我的工作方式几乎完全符合我的要求。现在，我需要能够在比较文件之前添加从文件中删除数据的功能。

原因是每次保存文件时，已知删除的字符串＆＃34;数据＆＃34;

我写了一个正则表达式来选择我要删除的确切文本，但是我在使用当前代码时无法实现它。

以下是三个主要功能

HOSTNAME_RE = re.compile(r'hostname +(\S+)')
def get_file_info_from_lines(filename, file_lines):
    hostname = None
    a_hash = hashlib.sha1()
    for line in file_lines:
        a_hash.update(line.encode('utf-8'))
        match = HOSTNAME_RE.match(line)
        if match:
            hostname = match.group(1)
    return hostname, filename, a_hash.hexdigest()

def get_file_info(filename):
    if filename.endswith(('.cfg', '.startup', '.confg')):
        with open(filename, "r+") as in_file:
            #filename = re.sub(REMOVE_RE, subst, filename, 0, re.MULTILINE)
            return get_file_info_from_lines(filename, in_file.readlines())

def hostname_parse(directory):
    results = {}
    i = 0
    l = len(os.listdir(directory))
    for filename in os.listdir(directory):
        filename = os.path.join(directory, filename)
        sleep(0.001)
        i += 1
        progress_bar(i, l, prefix = 'Progress:', suffix = 'Complete', barLength = 50)
        info = get_file_info(filename)
        if info is not None:
            results[info[0]] = info
    return results

这是查找要删除的字符串的正则表达式。

REMOVE_RE = r"((?:\bCurrent configuration)(?:.*\n?){6})"
subst = ""

EXAMPLE_FILE_BEFORE_DATA_REMOVED：

Building configuration...

Current configuration : 45617 bytes
!
! Last configuration change at 00:22:36 UTC Sun Jan 22 2017 by user
! NVRAM config last updated at 00:22:43 UTC Sun Jan 22 2017 by user
!
version 15.0
no service pad
!
no logging console
enable secret 5 ***encrypted password***
!
username admin privilege 15 password 7 ***encrypted password***
username sadmin privilege 15 secret 5 ***encrypted password***
aaa new-model
!
ip ftp username ***encrypted password***
ip ftp password 7 ***encrypted password***
ip ssh version 2
!
line con 0
 password 7 ***encrypted password***
 login authentication maint
line vty 0 4
 password 7 ***encrypted password***
 length 0
 transport input ssh
line vty 5 15
 password 7 ***encrypted password***
 transport input ssh
!

EXAMPLE_FILE_AFTER_DATA_REMOVED：

Building configuration...

!
no service pad
!
no logging console
enable 
!
username admin privilege 15 
username gisadmin privilege 15 
aaa new-model
!
ip ftp username cfgftp
ip ftp 
ip ssh version 2
!
line con 0

 login authentication maint
line vty 0 4

 length 0
 transport input ssh
line vty 5 15

 transport input ssh
!

我已尝试在get_file_info和get_file_info_from_lines中执行类似#filename = re.sub（REMOVE_RE，subst，filename，0，re.MULTILINE）之类的操作，但我显然没有正确实现它。

任何帮助都会受到赞赏，因为我正在学习。

运行比较：

results1 = hostname_parse('test1.txt')
results2 = hostname_parse('test2.txt')



for hostname, filename, filehash in results1.values():
    if hostname in results2:
        _, filename2, filehash2 = results2[hostname]
        if filehash != filehash2:
            print("%s has a change (%s, %s)" % (
                hostname, filehash, filehash2))
            print(filename)
            print(filename2)
            print()

我不想修改当前文件。如果所有这一切都可以在内存中完成，或者临时文件会很棒。

完整代码：

import hashlib
import os
import re


HOSTNAME_RE = re.compile(r'hostname +(\S+)')
REMOVE_RE = re.compile(r"((?:\bCurrent configuration)(?:.*\n?){6})")


def get_file_info_from_lines(filename, file_lines):
    hostname = None
    a_hash = hashlib.sha1()
    for line in file_lines:
        #match = HOSTNAME_RE.match(line)
        if not re.match(REMOVE_RE, line):
            a_hash.update(line.encode('utf-8'))
        #=======================================================================
        # if match:
        #     hostname = match.group(1)
        #=======================================================================
    return hostname, filename, a_hash.hexdigest()

def get_file_info(filename):
    if filename.endswith(('.cfg', '.startup', '.confg')):
        with open(filename, "r+") as in_file:
            return get_file_info_from_lines(filename, in_file.readlines())

def hostname_parse(directory):
    results = {}
    for filename in os.listdir(directory):
        filename = os.path.join(directory, filename)
        info = get_file_info(filename)
        if info is not None:
            results[info[0]] = info
    return results


results1 = hostname_parse('test1') #Directory of test files
results2 = hostname_parse('test2') #Directory of test files 2



for hostname, filename, filehash in results1.values():
    if hostname in results2:
        _, filename2, filehash2 = results2[hostname]
        if filehash != filehash2:
            print("%s has a change (%s, %s)" % (
                hostname, filehash, filehash2))
            print(filename)
            print(filename2)
            print()

Answer 1

在get_file_info_from_lines中，如果与正则表达式匹配，则忽略该行。这样您就不需要实际修改文件或创建另一个文件，只需使用实际重要的行来计算哈希值。

for line in file_lines:
    if not re.match(REMOVE_RE, line):
        a_hash.update(line.encode('utf-8'))

Answer 2

我能够在正则表达式周围寻找方法。我只是通过匹配该行来删除这些行。

def get_file_info_from_lines(filename, file_lines):
    hostname = None
    a_hash = hashlib.sha1()
    for line in file_lines:
        if "! Last " in line:
            line = ''
        if "! NVRAM " in line:
            line = ''
        a_hash.update(line.encode('utf-8'))
        match = HOSTNAME_RE.match(line)
        if match:
            hostname = match.group(1)

使用正则表达式替换文件数据

2 个答案: