How do I clean up empty lines in a configparser file?

Question

I sometimes get an .ini file that looks like this after changing and deleting values:

[Section A]
x = 1
d = 2



[Section B]
a = 3

Is there an easy way to keep it clean and remove those blank lines between the sections?

Answer 1

If you want to use a strictly python solution, you can create a temp file, copy over the non empty lines, and then replace the file.

from tempfile import mkstemp
from os import close
from shutil import move

def replace(filename, name, new_value):
    fd, path = mkstemp()
    with open(path,'w') as tmpfile:
        with open(filename) as csv:
            for line in cvs:
                if line.strip()!="":
                    tmpfile.write(line)
    close(fd)
    move(path, filename)

Answer 2

Probably easier using a tool like grep

$ grep -v "^\\s*$" foo > bar

but if you have to use Python then check out this answer .

Answer 3

Just use sed:

sed '/^$/d' myfile.ini

works

Answer 4

Maybe this can work:

lines = open("file").readlines()

n_lines = ["%s" % line for line in lines if line.strip()]

f = open("file", "w")
f.write("".join(n_lines))
f.close()

I use the list comprehension and create a new variable with the filter lines.

EDIT

If you can add a linebreak for each section, this maybe can work:

lines = open("file").readlines()

n_lines = ["\n%s" % line if "[Sect" in line else line for line in lines if line.strip()]

f = open("file", "w")
f.write("".join(n_lines).lstrip())
f.close()

EDIT 2:

I'm not sure... but

If your file is so large and the Python that you work is 3 version, maybe you can use this code for better performance:

def readfile(filepath): 
    with open(filepath, "r") as f: 
        for line in f:
            yield line

lines = readfile("file")

n_lines = ["\n%s" % line if "[Sect" in line else line for line in lines if line.strip()]

f = open("file", "w")
f.write("".join(n_lines).lstrip())
f.close()

Reference