如何在Python中返回整个字符串并从中提取列？ [关闭]

Posted 2021-03-26

例如，从这个输出中，我需要带有单词'test1.txt'的字符串，然后我需要该字符串中的第三列，即文件大小。像Linux中的“cut”命令

5636335  -rw-        1922  Apr 20 2019 09:22:47 +00:00  private-config.cfg
5636332  -rw-        1136  Apr 20 2019 09:22:47 +00:00  NETMAP
5636336  -rw-        0     Apr 20 2019 13:14:51 +00:00  test1.txt
5636325  -rw-        1691  Apr 20 2019 09:22:47 +00:00  startup-config.cfg
5636333  -rw-       16384  Apr 20 2019 09:22:47 +00:00  nvram_00001
5636330  -rw-         341  Apr 20 2019 09:22:47 +00:00  ubridge.log

NETMIKO module
net_connect = ConnectHandler(**cisco)
output = net_connect.send_command('dir')
x = re.search('test1.txt', output)
print(x)

<re.Match object; span=(215, 224), match='test1.txt'>

答案

你可以切片[13:25]和strip()

output = '''5636335  -rw-        1922  Apr 20 2019 09:22:47 +00:00  private-config.cfg
5636332  -rw-        1136  Apr 20 2019 09:22:47 +00:00  NETMAP
5636336  -rw-        0     Apr 20 2019 13:14:51 +00:00  test1.txt
5636325  -rw-        1691  Apr 20 2019 09:22:47 +00:00  startup-config.cfg
5636333  -rw-       16384  Apr 20 2019 09:22:47 +00:00  nvram_00001
5636330  -rw-         341  Apr 20 2019 09:22:47 +00:00  ubridge.log'''

for row in output.split('\n'):
    if 'test1.txt' in row:
        print(row[13:25].strip())

列之间有很多空格，所以正常的split(' ')会创建太多的空列，它可能不起作用，但re.split("\s+")可以做到这一点

output = '''5636335  -rw-        1922  Apr 20 2019 09:22:47 +00:00  private-config.cfg
5636332  -rw-        1136  Apr 20 2019 09:22:47 +00:00  NETMAP
5636336  -rw-        0     Apr 20 2019 13:14:51 +00:00  test1.txt
5636325  -rw-        1691  Apr 20 2019 09:22:47 +00:00  startup-config.cfg
5636333  -rw-       16384  Apr 20 2019 09:22:47 +00:00  nvram_00001
5636330  -rw-         341  Apr 20 2019 09:22:47 +00:00  ubridge.log'''

import re

for row in output.split('\n'):
    if 'test1.txt' in row:
        print(re.split('\s+', row)[2])

另一答案

您可以使用：

tr -s ' ' <test1.txt | cut -d ' ' -f3

---

1922
1136
0
1691
16384
341

---

ts -s | squeeze-repeats
cut -d | delimiter
cut -f | field

---

我知道如何在Linux中完成它，我需要Python帮助

import re
sizes = [re.split(r"\s+", l)[2] for l in open("test1.txt").readlines()]
# ['1922', '1136', '0', '1691', '16384', '341']