重置i

Question

我一直试图创建一个csv文件，将改变所有的子网和IP地址范围，使没有重叠。原来的问题在这里Editing csv file to edit subnets so there is no overlap in IP ranges (ipaddress module in Python 3.3)，但我已经修复了它，所以if语句停止了ValueError，第二个问题实际上不是问题。我相信，如果我能重置迭代器，我可以使这项工作。它需要比较文件1中的每一行和文件2中的每一行。你知道吗

当我尝试这个：

import ipaddress
import csv
from csv import DictReader, DictWriter

with open(r'file1.csv', newline='') as fin3,\
     open(r'file2.csv', newline='') as fin4,\
     open(r'file3.csv', 'w', newline='') as fout3:


    read3 = DictReader(fin3) # fin 3 and 4 are copies of the same file
    read4 = DictReader(fin4)

    writenum3 = DictWriter(fout3, fieldnames=read3.fieldnames) 
    writenum3.writeheader()

    for line3 in read3:
        line3['Range']=ipaddress.ip_network(line3['Range']) # Convert IP ranges to ip network object
        for line4 in read4:
            line4['Range']=ipaddress.ip_network(line4['Range']) # Convert IP ranges to ip network object
            if line3['Range'].netmask < line4['Range'].netmask: # To avoid "Not contained in" errors
                if line3['Range'].overlaps(line4['Range']): # Tests for IP overlap
                    lst=list(line3['Range'].address_exclude(line4['Range'])) # List of subnets excluding line4 subnet
                    print (lst) # Temporary to view contents of lst
                    for val in lst:
                        line3['Range']=val # New range
                        line3[' IPStart']=val.network_address #New net address
                        line3[' IPStop']=val.broadcast_address #New broadcast address
                        writenum3.writerow(line3) # Write lines

它只比较file1的第一行（不是头）和file2的第二行（不是头）。你知道吗

当我有这个（使用file.seek(0)）：

import ipaddress
import csv
from csv import DictReader, DictWriter

with open(r'file1.csv', newline='') as fin3,\
     open(r'file2.csv', newline='') as fin4,\
     open(r'file3.csv', 'w', newline='') as fout3:


    read3 = DictReader(fin3) # fin 3 and 4 are copies of the same file
    read4 = DictReader(fin4)

    writenum3 = DictWriter(fout3, fieldnames=read3.fieldnames) 
    writenum3.writeheader()

    for line3 in read3:
        line3['Range']=ipaddress.ip_network(line3['Range']) # Convert IP ranges to ip network object
        fin4.seek(0)
        for line4 in read4:
            line4['Range']=ipaddress.ip_network(line4['Range']) # Convert IP ranges to ip network object
            if line3['Range'].netmask < line4['Range'].netmask: # To avoid "Not contained in" errors
                if line3['Range'].overlaps(line4['Range']): # Tests for IP overlap
                    lst=list(line3['Range'].address_exclude(line4['Range'])) # List of subnets excluding line4 subnet
                    print (lst) # Temporary to view contents of lst
                    for val in lst:
                        line3['Range']=val # New range
                        line3[' IPStart']=val.network_address #New net address
                        line3[' IPStop']=val.broadcast_address #New broadcast address
                        writenum3.writerow(line3) # Write lines

它给出了一个错误ValueError: 'Range' does not appear to be an IPv4 or IPv6 network。你知道吗

如果我尝试list()方法（这里解释：Can iterators be reset in Python?）：

import ipaddress
import csv
from csv import DictReader, DictWriter

with open(r'file1.csv', newline='') as fin3,\
     open(r'file2.csv', newline='') as fin4,\
     open(r'file3.csv', 'w', newline='') as fout3:


    read3 = list(DictReader(fin3)) # fin 3 and 4 are copies of the same file
    read4 = list(DictReader(fin4))

    writenum3 = DictWriter(fout3, fieldnames=read3.fieldnames) 
    writenum3.writeheader()

    for line3 in read3:
        line3['Range']=ipaddress.ip_network(line3['Range']) # Convert IP ranges to ip network object
        fin4.seek(0) # Reset iterator
        for line4 in read4:
            line4['Range']=ipaddress.ip_network(line4['Range']) # Convert IP ranges to ip network object
            if line3['Range'].netmask < line4['Range'].netmask: # To avoid "Not contained in" errors
                if line3['Range'].overlaps(line4['Range']): # Tests for IP overlap
                    lst=list(line3['Range'].address_exclude(line4['Range'])) # List of subnets excluding line4 subnet
                    print (lst) # Temporary to view contents of lst
                    for val in lst:
                        line3['Range']=val # New range
                        line3[' IPStart']=val.network_address #New net address
                        line3[' IPStop']=val.broadcast_address #New broadcast address
                        writenum3.writerow(line3) # Write lines

它给出了AttributeError: 'list' object has no attribute 'fieldnames'错误。你知道吗

我想知道我是否应该使用http://docs.python.org/3.4/library/itertools.htmltee()来实现这一点，但我不知道如何在这里使用它，或者它是否可以工作。你知道吗

这是我的文件1和文件2：

Zone Name, IPStart, IPStop,Range,Source
Group A,10.0.0.0,10.127.255.255,10.0.0.0/9,New List
Group A Sales,10.16.0.0,10.31.255.255,10.16.0.0/12,New List
Group A Marketing,10.62.0.0,10.62.255.255,10.62.0.0/16,New List
Group A Research,10.62.0.0,10.63.255.255,10.62.0.0/15,Old List
Group A Sales Primary routers,10.23.1.0,10.23.1.15,10.24.1.0/28,New List
Group A Sales Web Servers - Primary,10.18.0.0,10.18.0.255,10.18.0.0/24,New List
Group A Sales Web Servers,10.16.0.0,10.19.255.255,10.16.0.0/14,New List
Group B,10.128.0.0,10.255.255.255,10.128.0.0/9,Old List

这就是我最终想要的（尽管每个比较的所有子网现在都可以）：

Zone Name, IPStart, IPStop,Range,Source
Group A,10.0.0.0,10.15.255.255,10.0.0.0/12,New List
Group A,10.32.0.0,10.47.255.255,10.32.0.0/12,New List
Group A,10.48.0.0,10.55.255.255,10.48.0.0/13,New List
Group A,10.56.0.0,10.59.255.255,10.56.0.0/14,New List
Group A,10.60.0.0,10.61.255.255,10.60.0.0/15,New List
Group A,10.64.0.0,10.127.255.255,10.64.0.0/10,New List
Group A Marketing,10.62.0.0,10.62.255.255,10.62.0.0/16,New List
Group A Research,10.63.0.0,10.63.255.255,10.63.0.0/16,Old List
Group A Sales,10.20.0.0,10.21.255.255,10.20.0.0/15,New List
Group A Sales,10.22.0.0,10.22.255.255,10.22.0.0/16,New List
Group A Sales,10.23.0.0,10.23.0.255,10.23.0.0/24,New List
Group A Sales,10.23.1.128,10.23.1.255,10.23.1.128/25,New List
Group A Sales,10.23.1.16,10.23.1.31,10.23.1.16/28,New List
Group A Sales,10.23.1.32,10.23.1.63,10.23.1.32/27,New List
Group A Sales,10.23.1.64,10.23.1.127,10.23.1.64/26,New List
Group A Sales,10.23.128.0,10.23.255.255,10.23.128.0/17,New List
Group A Sales,10.23.16.0,10.23.31.255,10.23.16.0/20,New List
Group A Sales,10.23.2.0,10.23.3.255,10.23.2.0/23,New List
Group A Sales,10.23.32.0,10.23.63.255,10.23.32.0/19,New List
Group A Sales,10.23.4.0,10.23.7.255,10.23.4.0/22,New List
Group A Sales,10.23.64.0,10.23.127.255,10.23.64.0/18,New List
Group A Sales,10.23.8.0,10.23.15.255,10.23.8.0/21,New List
Group A Sales,10.24.0.0,10.31.255.255,10.24.0.0/13,New List
Group A Sales,10.24.32.0,10.24.63.255,10.24.32.0/19,New List
Group A Sales Primary routers,10.23.1.0,10.23.1.15,10.24.1.0/28,New List
Group A Sales Web Servers,10.16.0.0,10.17.255.255,10.16.0.0/15,New List
Group A Sales Web Servers,10.19.0.0,10.19.255.255,10.19.0.0/16,New List
Group A Sales Web Servers,10.18.128.0,10.18.255.255,10.18.128.0/17,New List
Group A Sales Web Servers,10.18.64.0,10.18.127.255,10.18.64.0/18,New List
Group A Sales Web Servers,10.18.32.0,10.18.63.255,10.18.32.0/19,New List
Group A Sales Web Servers,10.18.16.0,10.18.31.255,10.18.16.0/20,New List
Group A Sales Web Servers,10.18.8.0,10.18.15.255,10.18.8.0/21,New List
Group A Sales Web Servers,10.18.4.0,10.18.7.255,10.18.4.0/22,New List
Group A Sales Web Servers,10.18.2.0,10.18.3.255,10.18.2.0/23,New List
Group A Sales Web Servers,10.18.1.0,10.18.1.255,10.18.1.0/24,New List
Group A Sales Web Servers - Primary,10.18.0.0,10.18.0.255,10.18.0.0/24,New List
Group B,10.128.0.0,10.255.255.255,10.128.0.0/9,Old List

任何帮助都是感激的，让这个工作应该如何。你知道吗

谢谢你， B0T型

Answer 1

如果您想将DictReader/Writer子类化，那么您将需要另一个方法来重置该类。你知道吗

对于DictReader：

f = open(filename, "rb")
d = csv.DictReader(f, delimiter=",")

f.seek(0)
d.__init__(f, delimiter=",")

对于DictWriter：

f = open(filename, "rb+")
d = csv.DictWriter(f, fieldnames=fields, delimiter=",")

f.seek(0)
f.truncate(0)
d.__init__(f, fieldnames=fields, delimiter=",")
d.writeheader()
f.flush()

Answer 2

我认为您只需要在第二次尝试中在fin4.seek(0) # Reset iterator之后插入一个read4 = DictReader(fin4)，这样DictReader实例也会从文件的开头开始。你知道吗