Delete ^L character in a log file

Question

I want to delete all the characters "\L" that I find when i read the file. I tried to use this function when I read a line:

def cleanString(self, s):
            if isinstance(s, str):
                    s = unicode(s,"iso-8859-1","replace")
                    s=unicodedata.normalize('NFD', s)
                    return s.encode('ascii', 'ignore')

But it doesn't delete this character. Does someone know how to do it?

I tried using the replace function as well, but it is not better:

s = line.replace("\^L","")

Thanks for your answers.

The Python representation of `^L` is `'\x0c'` or `'\f'`. – Mark Ransom Jun 18 '14 at 14:58 — Mark Ransom, Jun 18 '14 at 14:58

score 4 · Accepted Answer · answered Jun 18 '14 at 14:56

4

Probably you have not the literal characters ^ and L, but something that is displayed as ^L.

This would be the form feed character.

So do s = line.replace('\x0C', '').

answered Jun 18 '14 at 14:56

glglgl

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HO I can't believe that it was that simple. Thank you i was on that problem since this morning ;) – Kvasir Jun 18 '14 at 15:02

score 2 · Answer 2 · answered Jun 18 '14 at 14:57

^L (codepoint 0C) is an ASCII character, so it won't be affected by an encoding to ASCII. You could filter out all control characters using a small regex (and, while you're at it, filter out everything non-ASCII as well):

import re
def cleanString(self, s):
    if isinstance(s, str):
        s = unicode(s,"iso-8859-1","replace")
        s = unicodedata.normalize('NFD', s)
        s = re.sub(r"[^\x20-\x7f]+", "", s)  # remove non-ASCII/nonprintables
        return str(s)                        # No encoding necessary

Mark Ransom · Answer 3 · 2014-06-18T15:10:48.650

You almost had it correct, you just need a different representation for ^L.

s = line.replace("\x0c", "")

Here's a function that will return the representation of any control character.

def cc(ch):
    return chr(ord(ch) & 0x1f)

>>> cc('L')
'\x0c'

Some control characters have alternate representations, the common ones being '\r' for ^M and '\n' for ^J. These are listed in a chart in the documentation for string literals based on the name given in an ASCII control code chart.

Delete ^L character in a log file

3 Answers3