Copylines = []
lines.append('def print_success():')
lines.append('    print "sucesss"')
"\n".join(lines)

If you're building something complex dynamically:

Copyclass CodeBlock():
    def __init__(self, head, block):
        self.head = head
        self.block = block
    def __str__(self, indent=""):
        result = indent + self.head + ":\n"
        indent += "    "
        for block in self.block:
            if isinstance(block, CodeBlock):
                result += block.__str__(indent)
            else:
                result += indent + block + "\n"
        return result

You could add some extra methods, to add new lines to the block and all that stuff, but I think you get the idea..

Example:

Copyifblock = CodeBlock('if x>0', ['print x', 'print "Finished."'])
block = CodeBlock('def print_success(x)', [ifblock, 'print "Def finished"'])
print block

Output:

Copydef print_success(x):
    if x>0:
        print x
        print "Finished."
    print "Def finished."

You need to change the second flag when opening the file:

• w for only writing (an existing file with the same name will be erased)
• a opens the file for appending

Your code then should be:

with open("output.txt", "a") as f:

You need to open the file again using open(), but this time passing 'w' to indicate that you want to write to the file. I would also recommend using with to ensure that the file will be closed when you are finished writing to it.

with open('Failed.txt', 'w') as f:
    for ip in [k for k, v in ips.iteritems() if v >=5]:
        f.write(ip)

Naturally you may want to include newlines or other formatting in your output, but the basics are as above.

The same issue with closing your file applies to the reading code. That should look like this:

ips = {}
with open('today','r') as myFile:
    for line in myFile:
        parts = line.split(' ')
        if parts[1] == 'Failure':
            if parts[0] in ips:
                ips[pars[0]] += 1
            else:
                ips[parts[0]] = 0