Question

好，我目前有以下代码：

n = 0
with open('/home/user/test.filter') as f:

    lines = f.readlines()

    for l in lines:
        if lines[n].startswith('-A vlan_8'):
            if "-o bond1.8" in lines[n]:
                    f = open('vlan8.filter_in', 'a')
                    f.write(l)
            else:
                f = open('vlan8.filter_out', 'a')
                f.write(l)
        if lines[n].startswith('-A vlan_10'):
            if "-o bond1.10" in lines[n]:
                f = open('vlan10.filter_in', 'a')
                f.write(l)
            else:
                f = open('vlan10.filter_out', 'a')
                f.write(l)
        if lines[n].startswith('-A vlan_15'):
            if "-o bond1.15" in lines[n]:
                f = open('vlan15.filter_in', 'a')
                f.write(l)
            else:
                f = open('vlan15.filter_out', 'a')
                f.write(l)

        # [...]

        n = n + 1

我想过用一些累加器或列表来优化它，以免使脚本如此广泛。有什么建议吗？

Answer 1

当然可以。保持这些数字的列表如下：

numList = [8, 10, 15, ...]

现在，您只需要一个小字符串格式化。

with open('/home/user/test.filter') as f:
    lines = f.readlines()

for i, l in enumerate(lines): # I've used enumerate to eliminate n but really you don't need it
    for num in numList:
        if l.startswith('-A vlan_%d' %num):
            if "-o bond1.%d" %num in l:
                f = open('vlan%d.filter_in' %num, 'a')
            else:
                f = open('vlan%d.filter_out' %num, 'a')

            f.write(l)
            f.close()
            break

Answer 2

我认为您希望使代码更清晰，而不是更快。如果是这样，也许这会奏效：

import re

parameter_re = re.compile(r'^-A vla_(\d+).*')

with open('data.csv') as f:
    lines = f.readlines()

for line in lines:
    # Match required parameter
    match = parameter_re.match(line)

    # Skip line if it doesn't match the required parameter
    if not match:
        continue

    # Extract number from parameter
    number = int(match.group(1))

    # Create output parameter string
    output_str = '-o bond1.%d' % number

    # Select correct filename to save the line
    if output_str in line:
        output_filename = 'vlan%d.filter_in' % number
    else:
        output_filename = 'vlan%d.filter_out' % number

    # Write the line to the correct file
    with open(output_filename, 'a') as f:
        f.write(line)

如果你想让它更短（我不推荐，最好是可读）：

import re

with open('data.csv') as f:
    lines = f.readlines()

for line in lines:
    match = re.match(r'^-A vla_(\d+).*', line)
    if not match:
        continue
    number = int(match.group(1))
    if '-o bond1.%d' % number in line:
        output_filename = 'vlan%d.filter_in' % number
    else:
        output_filename = 'vlan%d.filter_out' % number
    with open(output_filename, 'a') as f:
        f.write(line)

优化python中的for循环

2 个答案: