Brain Goo » Programming

Python HOWTO Push a Dict on to a List (push a hash on to an array)

admin — Fri, 23 Apr 2010 14:37:37 +0000

One of my more popular posts is How to Push a Hash on to an Array in PERL, but how do you push a dict on to a list in Python?

Lists are one-dimensional arrays and dicts are associative arrays or hash arrays. This means we can do the same thing we do in other languages, with syntax to match Python’s object-oriented data structures.

import pprint

# Define the list somelist = []

# Do add some elements to the list somelist.append({'key1':'value1', 'key2': 'value2'}) somelist.append({'key1':'value1', 'key2': 'value2'}) somelist.append({'key1':'value1', 'key2': 'value2'})

# Print it out pp = pprint.PrettyPrinter(indent=4) pp.pprint(somelist)

Will give you:

[ { 'key1': 'value1', 'key2': 'value2'}, { 'key1': 'value1', 'key2': 'value2'}, { 'key1': 'value1', 'key2': 'value2'}]

PERL How To Print A List Without A Loop

admin — Fri, 06 Feb 2009 16:47:19 +0000

PERL has a built-in function called join() that will concatenate a list with a given string. The official perldoc states:

join EXPR,LIST
Joins the separate strings of LIST into a single string with fields separated by the value of EXPR, and returns that new string. Example:
$rec = join(':', $login,$passwd,$uid,$gid,$gcos,$home,$shell);

From the code example, you can make CSV output and all kinds of goodies, but what the doc misses and the example doesn’t show is that combining join() with a print statement makes writing lists to STDOUT or a file handle a snap. This is where join() really shines.

Example:

Code
@names = ('Mark', 'Jim', 'Bob','Mary','Steven','Gomer'); print join("\n", @names);

Output
Mark
Jim
Bob
Mary
Steven
Gomer

Note that this will NOT print a final or beginning string. Join() concatenates the elements, meaning it puts the string value BETWEEN the list elements.

Did you find this post useful or have questions or comments? Please let me know!

perl howto push a hash onto an array

admin — Tue, 12 Aug 2008 20:59:47 +0000

use Data::Dumper; my @array; push @array, {'key1' => 'value1', 'key2' => 'value2'}; push @array, {'key1' => 'value1', 'key2' => 'value2'}; push @array, {'key1' => 'value1', 'key2' => 'value2'}; print Dumper(@array);

Will give you:
$VAR1 = { 'key2' => 'value2', 'key1' => 'value1' }; $VAR2 = { 'key2' => 'value2', 'key1' => 'value1' }; $VAR3 = { 'key2' => 'value2', 'key1' => 'value1' };

Snazzy!

Did you find this post useful or have questions or comments? Please let me know!

Quick Character Escaping in PHP

admin — Wed, 10 Oct 2007 17:48:14 +0000

When writing PHP web apps, I tend to run in to a portability issue when dealing with SQL connectivity. Since I can’t count on having the PEAR DB module available, I rolled my own set of functions to interact with a MySQL database.

The problem lies in escaping characters in your SQL queries. Do I addslashes()? Is magic_quotes_gpc enabled?

My quick-and-dirty solution is the following function:

function request_cleanup() { if(get_magic_quotes_gpc() == 0) { foreach($_REQUEST as $req_key => $req_value) { $_REQUEST[$req_key]=addslashes($_REQUEST[$req_key]); } } }

By calling that function on every page that deals with inserting content in to the database, I know will will get my content escaped correctly.

Of course it escapes all submitted content, including that which isn’t going in to the database so don’t forget to stripslashes() when you are working with data that doesn’t need it.

Example:
request_cleanup();


$notes = $_REQUEST['notes '];

$confirmation = stripslashes($_REQUEST['notes ']);
$SQL = "INSERT INTO notes (note) VALUES ('$notes')";

sql_proc($SQL);

print "Your note was: $confirmation";

Perl code to find an IP A in subnet B/C

admin — Tue, 05 Jun 2007 22:14:39 +0000

my $ip = '1.2.3.4';
my $block1 = '1.2.3.0/27';

if(checkip($ip, $block1)) {
    print STDOUT "$ip is in $block1\n";
}
else {
    print STDOUT "$ip is not in $block1\n";
}

sub checkip() {
    my $ip = shift;
    my $block = shift;

    @ip1 = split(/\./, $ip);
    $ip1 = $ip1[0] * 2**24 + $ip1[1] * 2**16 + $ip1[2] * 2**8 + $ip1[3];
    my @temp = split(/\//, $block);

    $ip2 = $temp[0];
    my $netmask = $temp[1];

    @ip2 = split(/\./, $ip2);
    $ip2 = $ip2[0] * 2**24 + $ip2[1] * 2**16 + $ip2[2] * 2**8 + $ip2[3];

    if( $ip1 >> (32-$netmask) == $ip2 >> (32-$netmask) ) {
            return 1;
    }
    return 0;
}

PHP Header injection

admin — Mon, 21 May 2007 17:43:50 +0000

I regularly shut down web sites that use the PHP mail() function. While the users of the sites mean well, they generally don’t do any checking before sending data to mail(). I’m not going to weigh in mail(). Enough has been said about it. Just remember to take your code and code security seriously.

Remember, never trust data submitted by site visitors. Sanitize the heck out of it.

Jelly and Custard has an excellent explanation of PHP Header Injection when using the PHP mail() function.

http://www.jellyandcustard.com/2006/02/24/email-header-injection-in-php/

http://www.jellyandcustard.com is an excellent PHP blog.

Panic Releases Coda, and I can’t use it

admin — Thu, 17 May 2007 16:54:56 +0000

http://www.panic.com/ released Coda a web-oriented IDE that contains a terminal, FTP, SSH, etc. all rolled in to one. It looks great and I want it, but it’s Mac only. Some day…