Insert a block of executable code. Note that a NEWLINE must be after the code keyword. From that point the text is passed to the Python interpreter. The node wil be removed from the output.

<example-code>
<?xpt code
import libxml2
import xpt

def myFunction(nd,arg1):
    return "myFunction: nd="+nd.name+" arg1='"+arg1+"'"

xpt.registerfunction("myFunction")?></example-code>

<example-call>
<?xpt myFunction "an argument"?>
</example-call>

In the example above, the first processing-instruction using the code statement registers a new xpt function called myFunction which is associated with the Python function with the same name. After evaluation it will be removed from the output. In the second processing-instruction the xpt function is evaluated. It will be replaced with the result returned by the Python function, in example Example 1, “example built-in code usage” that is the string "myFunction: nd=xpt arg1='an argument'".

In Python a module variable __xpt_code_xmlNode__ is set to the libXML2 node containing the current code statement. The variable is removed when the execution of the module stops.

	Note
	All Python functions that are called from xpt have at least one argument, i.e. a xmlNode pointer referencing the XML element from where the actual call originates. In this is the example-call element.

See also Section 6.1.6, “loadmodule”. xpt.debug

Debugging command which displays the current document to the standard error output, using STRING as a message. Note that debugging output must be enabled by using option -x or environment variable.

Debugging command which shows a list of currently defined variables to the standard error output, using STRING as a message. Note that debugging output must be enabled by using option -x or environment variable.

Evaluate STRING and replace the processing-instruction by the string representation.

See also Section 6.1.8, “get”.

Evaluate STRING, report it on the standard error channel and stop processing of the input. No output file will be written. The xpt process returns an exit-code of 1 to the parent process.

Load Python module MODULE. The node wil be removed from the output.

<?xpt showNextPI?>

See also ???.

Replace the processing-instruction with the result of the python-expression.

Replace the processing-instruction with the value of variable NAME.

<?xpt get __hostname__?>

Here See also Section 6.1.4, “echo”.

Replace the processing-instruction with the result of the XPATH expression. If NAME is given the result is saved in a variable and the processing-instruction is removed from the output.

Create or replace variable NAME with value VALUE. The node wil be removed from the output.

<?xpt set var1 "**** This is var1 ****"?>

In the example above, var1 will have value **** This is var1 ****.

CASE-like expression

Replace the processing-instruction with the value of the shell command CMD.

Evaluate string MSG and send it to the standard error output. The processing-instruction is removed from the output.

import xpt

Issue a message on the debug output channel. See -x.

import xpt

Write list of XPT variables on the debug output channel. See -x and Section 6.1.3, “dumpvars”.

import xpt

Write a message to the standard error channel and stop processing of the input. See Section 6.1.5, “error”.

Get value of a variable. An exception is raised if the variable does not exist.

import xpt

Registers xpt function name which is associated with the Python function func. If this second parameter is not specified, it's name is assumed to be identical to name prefixed with the name of the module from which the registerfunction is called.

import xpt

Write a message to the standard error channel. See Section 6.1.13, “warning”.

There are several way of extending xpt. First by pointing xpt where the Python modules are using the -I option. A second way is by extending the library, giving you an opportunity to enter the XPT Hall of Fame.