Un-write

[Scriptr]

Intro:
I am a procrastinator. I start to do work and end up on facebook or otherwise.
There exists an app for OS X, Self-Control. It uses the hosts file to redirect requests to localhost.
However, such an app is not near the surface of google (and if it is, don't tell me. I'm nearly done writing it) for windows.

Meat of the Post:
I have a File IO class that writes and "unwrites" to the host file:

def write_to_hosts(ip_string, hosts):
    f = open(hosts, "a")
    f.write(ip_string)
    f.close()

def un_write(ip_string, hosts):
    print "IP list: \n", ip_string
    
    f = open(hosts, "r")
    h_text = f.read()
    f.close()
    
    print "hosts file:\n"+h_text
    
    h_text.replace(ip_string, "")
    
    print "hosts file:\n"+h_text

    f = open(hosts, "w")
    f.write(h_text)
    f.close()

The problem lies in the un_write(ip_string, hosts). It doesn't un-write. (note, the print statements are only for debugging purposes). It writes it back exactly how it was.

What am I doing wrong here?

[patryk]

why would you write classes for that stuff?
check 'grep', 'sed' and 'echo' utilities. that's all you need.
you have sources for those. just recompile (i'm sure you'll finde ports) for your system and use them

[Scriptr]

Originally Posted by patryk

why would you write classes for that stuff?
check 'grep', 'sed' and 'echo' utilities. that's all you need.
you have sources for those. just recompile (i'm sure you'll finde ports) for your system and use them

Not classes, so much as separate files.
I come from Java where the two are virtually synonymous, and the convention is one public class per file.

Also, I am aware of ports for shell commands, if that is what you are referring to, but I am not concerned about those. I am learning Python, which needn't be recompiled, and this is a simple project to help me learn as well as solve a practical problem.

No offense intended, but I would like an answer to the question asked, not a correction.