使用正则表达式替换文件数据

Question

在这里得到一些帮助,我的工作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我知道删除的字符串"数据"都不同.

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

这是用于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
!

我已经尝试在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,因为我只是在学习.

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.如果所有这些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

我能够找到解决正则表达式的方法。我只是通过匹配行来删除行。

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)