Question

problematic code:

out, err = shellcmd.run_get_out(shell_cmd, login_shell=True)
p = re.compile('^' + module + '/(.*)$')
m = p.match(out)
if m:
    return m.group(1)
return None

It get the output from some shell command and do a regular expression match. For example: out is ‘rvct/4.1_0894\n’ and module is ‘rvct’, it returns ‘4.1_0894’
But on some system, the shell command output starts with a new line, the out will be ‘\nrvct/4.1_0894\n’, I have to make this change

p = re.compile('^\n' + module + '/(.*)$')

to make it work

Can I have a regex working on both situations? I have tried

p = re.compile('^' + module + '/(.*)$', re.MULTILINE)

It seems not working.

Answer 1

You can strip newlines from the output first, using out.strip().