python 中提取以指定字符开头或指定字符结尾的数据

 

1、提取以x开头的行

[root@PC1 test]# ls
a.txt  test.py
[root@PC1 test]# cat a.txt
u r d
s f e
a d e
x v m
e f x
e r d
z d v
[root@PC1 test]# cat test.py       ## 提取以x开头的行
#!/usr/bin/python

in_file = open("a.txt", "r")
out_file = open("result.txt", "w")

lines = in_file.readlines()

for i in lines:
    if i.startswith("x"):
        out_file.write(i)

in_file.close()
out_file.close()
[root@PC1 test]# python test.py
[root@PC1 test]# ls
a.txt  result.txt  test.py
[root@PC1 test]# cat result.txt
x v m

 

2、提取以x开头或者以e开头的行

[root@PC1 test]# ls
a.txt  test.py
[root@PC1 test]# cat a.txt
u r d
s f e
a d e
x v m
e f x
e r d
z d v
[root@PC1 test]# cat test.py     ## 同时提取以x开头或者以e开头的数据
#!/usr/bin/python

in_file = open("a.txt", "r")
out_file = open("result.txt", "w")

lines = in_file.readlines()

for i in lines:
    if i.startswith("x") or i.startswith("e"):
        out_file.write(i)

in_file.close()
out_file.close()
[root@PC1 test]# python test.py
[root@PC1 test]# ls
a.txt  result.txt  test.py
[root@PC1 test]# cat result.txt
x v m
e f x
e r d

 

3、提取以e和d结尾的数据

[root@PC1 test]# ls
a.txt  test.py
[root@PC1 test]# cat a.txt
u r d
s f e
a d e
x v m
e f x
e r d
z d v
[root@PC1 test]# cat test.py       ## 提取以d或者以e结尾的数据
#!/usr/bin/python

in_file = open("a.txt", "r")
out_file = open("result.txt", "w")

lines = in_file.readlines()

for i in lines:
    if i.endswith("e\n") or i.endswith("d\n"):
        out_file.write(i)

in_file.close()
out_file.close()
[root@PC1 test]# python test.py
[root@PC1 test]# ls
a.txt  result.txt  test.py
[root@PC1 test]# cat result.txt
u r d
s f e
a d e
e r d

 

4、提取以x开头或者以e开头同时以x结尾的数据

[root@PC1 test]# ls
a.txt  test.py
[root@PC1 test]# cat a.txt
u r d
s f e
a d e
x v m
e f x
e r d
z d v
[root@PC1 test]# cat test.py   ## 提取以x开头，或者以e开头同时以x结尾的数据
#!/usr/bin/python

in_file = open("a.txt", "r")
out_file = open("result.txt", "w")

lines = in_file.readlines()

for i in lines:
    if (i.startswith("x")) or (i.startswith("e") and i.endswith("x\n")):
        out_file.write(i)

in_file.close()
out_file.close()
[root@PC1 test]# python test.py
[root@PC1 test]# ls
a.txt  result.txt  test.py
[root@PC1 test]# cat result.txt
x v m
e f x