如何在python的文本文件中首先搜索有空格的行

Question

I want to search lines contain specific a string in text file.

Example, I search lines contain strings umask 022 , not lines comment in /etc/profile file.

My codes:

def check_umask(fname, umask):
   with open(fname) as f:
       return any(umask in line for line in f)
check_umask('/etc/profile','umask 022')

With code in above, but it show lines comment:

# .....
# By default, we want ... umask 022
       # bla..bla... umask 022
.........
umask 022

So, how to show only lines contain umask 022 script, not lines comment?

Answer 1

You may use the combination of strip and startswith .

def check_umask(fname, umask):
   with open(fname) as f:
       for line in f:
           if not line.strip().startswith('#') and 'umask 022' in line:
               print line
check_umask('/etc/profile','umask 022')

Example:

>>> s = '''# .....
# By default, we want ... umask 022
       # bla..bla... umask 022
.........
umask 022'''.splitlines()
>>> for line in s:
    if not line.strip().startswith('#') and 'umask 022' in line:
        print line


umask 022
>>> 

or

for line in s:
    if re.search(r'^[^#]*umask 022', line):
        print line

Answer 2

mo = re.search(r'[^#]*umask 022', line)
if mo:
    print(mo.group())

Answer 3

You can use str.find() to compare indices. If a match isn't found, it returns -1, so we can turn that into a truthy/falsey value by adding 1:

for line in content:
    p = line.find('#') + 1
    u = line.find('umask 022') + 1
    if u and (not p or p > u):
        print(line)

Answer 4

I have again the other problems with my case. before "#" is a command valid.

export PATH=$PATH:/... # umask 022

So, @Raj's script still show this line, althrough it contain "umask 022" in comment. So, Have we solution???