How to delete blank lines in a text file on a windows machine

Question

I am trying to delete all blank lines in all YAML files in a folder. I have multiple lines with nothing but CRLF (using Notepad++), and I can't seem to eliminate these blank lines. I researched this before posting, as always, but I can't seem to get this working.

import glob
import re
path = 'C:\\Users\\ryans\\OneDrive\\Desktop\\output\\*.yaml'

for fname in glob.glob(path):
    with open(fname, 'r') as f:
        sfile = f.read()
        for line in sfile.splitlines(True):
            line = sfile.rstrip('\r\n')
            f = open(fname,'w')
            f.write(line)
            f.close()

Here is a view in Notepad++

I want to delete the very first row shown here, as well as all other blank rows. Thanks.

Answer 1

You cant write the file you are currently reading in. Also you are stripping things via file.splitlines() from each line - this way you'll remove all \\r\\n - not only those in empty lines. Store content in a new name and delete/rename the file afterwards:

Create demo file:

with open ("t.txt","w") as f:
    f.write("""

asdfb 

adsfoine 

""")

Load / create new file from it:

with open("t.txt", 'r') as r, open("q.txt","w") as w:
    for l in r:
        if l.strip(): # only write line if when stripped it is not empty
            w.write(l)

with open ("q.txt","r") as f:
   print(f.read())  

Output:

asdfb 
adsfoine 

( You need to strip() lines to see if they contain spaces and a newline. )

For rename/delete see fe How to rename a file using Python and Delete a file or folder

 import os os.remove("t.txt") # remove original os.rename("q.txt","t.txt") # rename cleaned one 

Answer 2

If you use python, you can update the line using:

re.sub(r'[\s\r\n]','',line)

Close the reading file handler before writing.

If you use Notepad++, install the plugin called TextFX.

1. Replace all occurances of \\r\\n with blank.
2. Select all the text
3. Use the new menu TextFX -> TextFX Edit -> E:Delete Blank Lines

I hope this helps.

Answer 3

It's nice and easy...

file_path = "C:\\Users\\ryans\\OneDrive\\Desktop\\output\\*.yaml"

with open(file_path,"r+") as file:
    lines = file.readlines()
    file.seek(0)
    for i in lines:
        if i.rstrip():
            file.write(i)

Where you open the file, read the lines, and if they're not blank write them back out again.