How do I remove the empty line from this file?

Question

I have this file called foo.txt and it has the following content:

# [empty line here]
bar 12
baz 34

the empty line is caused by removing everything in that line, here is the code:

newdict = {}
with open('foo.txt','r') as f:
    for line in f:
        if line.isalpha() == True: 
            splitline = line.split( )
            newdict[(splitline[0])] = ",".join(splitline[1:])
removethis = raw_input("Item to be removed: ")
if removethis in newdict:
    with open('foo.txt','r') as f:
        f.read()
    new = new.replace(removethis, '')
    with open('foo.txt','w') as f:
        f.write(new)
    with open('foo.txt','rw') as g:
        for line in g:
            if not line.isspace():
                g.write(line)

I want to remove the empty line from the file but nothing happens.

EDIT: To someone who marked this as duplicate, no thanks I don't want regex

It does automatically close, and what exactly do you want to do? I'm still a bit unclear. Do you just want to know how to remove empty lines from a file? — Silver, Jan 12 '17 at 16:55
Also, what's the purpose of `f.read()` inside the `if` statement? — Silver, Jan 12 '17 at 16:57
@silverslash yes, but not manually since I'd want to do it right after I remove something. When I remove something it leaves a gap, an empty line where it used to be in. After removal, I wanted to immediately edit the text file so that it would not have any empty space in it. — user7091717, Jan 12 '17 at 16:57
@SilverSlash I first need to read everything before I could make modifications. — user7091717, Jan 12 '17 at 17:00
Possible duplicate of [How to remove empty lines with or without whitespace in Python](http://stackoverflow.com/questions/3711856/how-to-remove-empty-lines-with-or-without-whitespace-in-python) — Ani Menon, Jan 12 '17 at 17:02

Mohammad Yusuf · Answer 1 · 2017-01-13T04:50:30.877

2

Try this:

with open('data/aa', 'rw') as f, open('data/aa2', 'w') as f2:
    newf = [a for a in f if a.strip()]
    f2.writelines(newf)

Or you can do it with sed as well (if you are on linux):

sed -i '/^\s*$/d' foo.txt

edited Jan 13 '17 at 04:50

answered Jan 12 '17 at 16:57

Mohammad Yusuf

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could you please explain what sed and '/^\s*$/d' mean? – user7091717 Jan 12 '17 at 17:07
@user7091717 Are you on linux? – Mohammad Yusuf Jan 12 '17 at 17:08
what does the `if a.strip()` do? doesn't it need to have some condition – user7091717 Jan 12 '17 at 17:21
and, doesn't .strip() also remove the spaces and line separation? – user7091717 Jan 12 '17 at 17:23
When you do `a.strip()` you will get empty string for lines containing only whitespaces. Empty string is considered as false and those lines will be skipped. `.strip()` removes whitespaces in a string on both the ends of string. – Mohammad Yusuf Jan 12 '17 at 17:27

How do I remove the empty line from this file?

1 Answers1