如何在从csv文件导入python时替换数字

Question

我目前正在编写一个Python脚本，以便从csv文件中提取数据，以利用Jinja2模板生成cisco ASR配置。所有这些都运行得很好；但是，我需要修改一行，以便生成的输出使用正确的ASR配置语法。我有数百个这样做，并希望能够简单地生成一个简单的复制和粘贴到设备的ASR配置正确。有人能指导我做这件事的最简单的方法吗？

我的Python脚本：

import os
import jinja2
import csv
import re

# csv fileused
csv_file = "BFL1_AR1.csv"
with open(csv_file) as f:
    read_csv = csv.DictReader(f)
    for list_elements in read_csv:
        generated_list = list_elements['TEST']
        generated_list = generated_list.split()
        list_elements['TEST'] = generated_list
        pattern = re.findall('4323:(\d{1,9})\:\DD', )
        print (pattern)

        template_file = 'asr_generate_config.j2'
        with open(template_file) as f:
            list_template = f.read()

        template = jinja2.Template(list_template)
        print()
        print('-' * 80)
        print(template.render(list_elements))
        print('-' * 80)
        print()

生成的输出：

--------------------------------------------------------------------------------
l2vpn bridge group 4323:63210:BD
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD mac withdraw state-down
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD mtu 9216
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD interface be10.149
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD interface be50.149
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD vfi 4323:63210:BD
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD vfi 4323:63210:BD vpn-id 1024571
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD vfi 4323:63210:BD autodiscovery bgp
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD vfi 4323:63210:BD autodiscovery bgp rd auto
l2vpn bridge group 4323:63210:BD bridge-domain 4323:63210:BD vfi 4323:63210:BD autodiscovery bgp route-target 4323:63210
interface be10.149 l2transport
interface be10.149 l2transport description CA/KXFN/201755/LVLC
interface be10.149 l2transport encapsulation dot1q 149
interface be10.149 l2transport rewrite ingress tag pop 1 symmetric
interface be10.149 l2transport ethernet-services access-group L2-FRAMES ingress
interface be50.149 l2transport
interface be50.149 l2transport description CA/KXFN/201755/LVLC
interface be50.149 l2transport encapsulation dot1q 149
interface be50.149 l2transport rewrite ingress tag pop 1 symmetric
interface be50.149 l2transport ethernet-services access-group L2-FRAMES ingress
--------------------------------------------------------------------------------

我需要改变的是：

具有以下数据格式的每个实例: 4323:63210:BD --> 4323_63210

每个客户的网桥组ID将保持不变。我需要将第一个分号改为下划线，并删除最后一个分号和B&D字母。我一直在尝试使用regex & re.findall来做这件事，但是一直没有太多的运气。

CSV文件：

AR Unit ID  AR_VLAN TEST    CIRCUIT oline lookup    uni lookup  oline dummy service reference   oline svlan assignment  oline_BD_assignment oline_RT_assignment oline_vpnid_assignment  end point node  ring id Add BFL1-AR1/ 6K Topology   New Router Port New_US_6K_Port  Add 6K / 7609 Topology  New_DS_6K_Port  New 6K Port
4   4   MATCH   66/KDFN/102901/TWCS 66/KDFN/102901/TWCS_O_Line  66/KDFN/102901/TWCS DUMMY_OLINE_SVC173  4   4323:63163:BD   4323:63163  1024524 BKFECAAAI6001   #N/A    00GZPP/GE1L/BKFECAAA/BKFECAAA   ae10.4  be10.4  00GZQB/GE1L/BKFECAAA/BKFECAAA   be50.4  Po50.4
15  15  MATCH   66/KEFN/102374/TWCS 66/KEFN/102374/TWCS_O_Line  66/KEFN/102374/TWCS DUMMY_OLINE_SVC176  15  4323:63166:BD   4323:63166  1024527 BKFECAUZW2001   N66200  00GZPP/GE1L/BKFECAAA/BKFECAAA   ae10.15 be10.15 00GZQB/GE1L/BKFECAAA/BKFECAAA   be50.15 Po50.15
39  39  MATCH   66/KEFN/102539/TWCS 66/KEFN/102539/TWCS_O_Line  66/KEFN/102539/TWCS DUMMY_OLINE_SVC177  39  4323:63167:BD   4323:63167  1024528 BKFDCA12NN001   N66204  00GZPP/GE1L/BKFECAAA/BKFECAAA   ae10.39 be10.39 00GZQB/GE1L/BKFECAAA/BKFECAAA   be50.39 Po50.39
50  50  MATCH   66/KFFN/102600/TWCS 66/KFFN/102600/TWCS_O_Line  66/KFFN/102600/TWCS DUMMY_OLINE_SVC203  50  4323:63193:BD   4323:63193  1024554 SHFTCADIW2001   N66198  00GZPP/GE1L/BKFECAAA/BKFECAAA   ae10.50 be10.50 00GZQB/GE1L/BKFECAAA/BKFECAAA   be50.50 Po50.50

Jinja2模板

l2vpn bridge group {{ oline_BD_assignment }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} mac withdraw state-down
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} mtu 9216
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} interface {{ New_US_6K_Port }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} interface {{ New_DS_6K_Port }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} vfi {{ oline_BD_assignment }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} vfi {{ oline_BD_assignment }} vpn-id {{ oline_vpnid_assignment }}
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} vfi {{ oline_BD_assignment }} autodiscovery bgp
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} vfi {{ oline_BD_assignment }} autodiscovery bgp rd auto
l2vpn bridge group {{ oline_BD_assignment }} bridge-domain {{ oline_BD_assignment }} vfi {{ oline_BD_assignment }} autodiscovery bgp route-target {{ oline_RT_assignment }}
interface {{ New_US_6K_Port }} l2transport
interface {{ New_US_6K_Port }} l2transport description {{CIRCUIT}}
interface {{ New_US_6K_Port }} l2transport encapsulation dot1q {{ AR_VLAN }}
interface {{ New_US_6K_Port }} l2transport rewrite ingress tag pop 1 symmetric
interface {{ New_US_6K_Port }} l2transport ethernet-services access-group L2-FRAMES ingress
interface {{ New_DS_6K_Port }} l2transport
interface {{ New_DS_6K_Port }} l2transport description {{CIRCUIT}}
interface {{ New_DS_6K_Port }} l2transport encapsulation dot1q {{ AR_VLAN }}
interface {{ New_DS_6K_Port }} l2transport rewrite ingress tag pop 1 symmetric
interface {{ New_DS_6K_Port }} l2transport ethernet-services access-group L2-FRAMES ingress

Answer 1

如果您的ID将始终采用通用格式：

pattern = r'(?P<name>[0-9]{4}:[0-9]{5})'
re.findall(pattern, test_value)
# Will return a list of matches, which you can then substitute the : for a _

或者，如果您想要更具体，以确保您也匹配:BD后缀：

pattern = r'(?P<name>[0-9]{4}:[0-9]{5}):[A-Z]{2}'

在获取更多详细信息后添加一些编辑：

def convert(old_id):
    pattern = r'(?P<name>[0-9]{4}:[0-9]{5})'
    matches = re.match(pattern, old_id)
    if matches:
        match=matches[0]
    else:
        return 'some_default'
    return match.replace(':','_')

或者不使用正则表达式：

def convert_simple(old_id):
    return '_'.join(old_id.split(':')[:2])

但是，这不会对ID的表单进行验证，因此，如果您确信csv中的ID都是正确的，那么就使用它。

您可以使用该方法将ID为:格式的表单转换为_格式的表单

然后，在您的代码中，我将使用以下命令获取旧ID

old_id = list_elements['oline_BD_assignment']
new_id = convert(old_id)
list_elements['oline_BD_assignment'] = new_id