Python regex search for string at beginning of line in file

Question

Here's my code:

#!/usr/bin/python
import io
import re
f = open('/etc/ssh/sshd_config','r')
strings = re.search(r'.*IgnoreR.*', f.read())
print(strings)

That returns data, but I need specific regex matching: e.g.:

^\s*[^#]*IgnoreRhosts\s+yes

If I change my code to simply:

strings = re.search(r'^IgnoreR.*', f.read())

or even

strings = re.search(r'^.*IgnoreR.*', f.read())

I don't get anything back. I need to be able to use real regex's like in perl

Answer 1

You can use the multiline mode then ^ match the beginning of a line:

#!/usr/bin/python
import io
import re
f = open('/etc/ssh/sshd_config','r')

strings = re.search(r"^\s*[^#]*IgnoreRhosts\s+yes", f.read(), flags=re.MULTILINE)
print(strings.group(0))

Note that without this mode you can always replace ^ by \n

Note too that this file is calibrated as a tomato thus:

^IgnoreRhosts\s+yes

is good enough for checking the parameter

---

EDIT: a better way

with open('/etc/ssh/sshd_config') as f:
    for line in f:
        if line.startswith('IgnoreRhosts yes'):
            print(line)

One more time there is no reason to have leading spaces. However if you want to be sure you can always use lstrip().