collections.deque 列队实现保留N个记录
file:
1 sh startup.sh
2 exit
3 cd /data/tomcat6/bin/
4 ps -ef |grep tomcat
5 top
6 ps -ef |grep tomcat
7 kill -9 12621
8 ps -ef |grep tomcat
9 sh startup.sh
10 exit
11 cd /data/tomcat6/bin/
12 ps -ef |grep tomcat
13 kill -9 24844
14 ps -ef |grep tomcat
15 sh startup.sh
16 exit
17 ps -ef |grep tomcat
18 cd /data/tomcat6/bin/
19 kill -9 23973
20 ps -ef |grep tomcat
例:
from collections import deque
def search(line,pattern,history=5):
previous_lines = deque(maxlen=history)
for li in line:
if pattern in li:
yield li,previous_lines
previous_lines.append(li)
if __name__ == '__main__':
"在 file 文件中,查找 'sh startup.sh' 字符串, 并且显示查找到'sh startup.sh' 字符串之前的5个记录"
with open('file') as f:
for line,previlnes in search(f,'sh startup.sh',5):
for piline in previlnes:
print(piline)
print(line)
print('_' * 20)
