python remove empty lines from file

1with open("new_file","r") as f:
2 for i in f.readlines():
3       if not i.strip():
4           continue
5       if i:
6           print i,
7

1import os
2
3
4def remove_empty_lines(filename):
5    if not os.path.isfile(filename):
6        print("{} does not exist ".format(filename))
7        return
8    with open(filename) as filehandle:
9        lines = filehandle.readlines()
10
11    with open(filename, 'w') as filehandle:
12        lines = filter(lambda x: x.strip(), lines)
13        filehandle.writelines(lines)   

1with open(fname, 'r+') as fd:
2    lines = fd.readlines()
3    fd.seek(0)
4    fd.writelines(line for line in lines if line.strip())
5    fd.truncate()
6