remove all blank lines using regular expressions

remove blank lines regex.md

REGEX remove blank lines:

FROM: http://www.ultraedit.com/support/tutorials_power_tips/ultraedit/remove_blank_lines.html

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FIND:

^(?:[\t ]*(?:\r?\n|\r))+

REPLACE:

[LEAVE THIS EMPTY BECAUSE YOU DO NOT WANT TO REPLACE WITH ANYTHING]

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(Related: If you happen to be where you can use AWK, you can use awk NF.
If you happen to be where you can use SED, you can use sed /^$/d' --
EXAMPLE USE OF SED sed /^$/d < text_with_blanks.txt > no_blanks.txt.)

Thanks mate

You can just use ^\s$ to match blank lines...

You can just use ^\s$ to match blank lines...

That's not a blank line. It's a line with exactly one whitespace character.

You can just use ^\s$ to match blank lines...

That's not a blank line. It's a line with exactly one whitespace character.

Oh... What about ^$?

Nope. A simple test would have shown it doesn't work. That's basically matching a zero width character. So replacing it with nothing has no effect. Here is a good thread to perhaps learn a bit more about removing empty lines. https://stackoverflow.com/questions/3866034/removing-empty-lines-in-notepad

This works for me (note the multiline flag):

EMPTY_LINES = re.compile(r'\n\s*\n', re.MULTILINE)
result = EMPTY_LINES.sub('\n', content)

Nope. A simple test would have shown it doesn't work. That's basically matching a zero width character. So replacing it with nothing has no effect. Here is a good thread to perhaps learn a bit more about removing empty lines. https://stackoverflow.com/questions/3866034/removing-empty-lines-in-notepad

Would this work: ^ *$? It should match the start of a string, then any amount of whitespace, then the end of a string.

Nope, that's still a line the contains a whitespace. It's not a blank line.

thats really helpful and I have replaced with a \n for my own convenience

Thanks!!!!

super helpful. big thanks