Processors are the core of Typus. Multiple processors are nested and chained in one single function to do things which may depend on the result returned by inner processors. Say, we set EscapeHtml and MyTrimProcessor, this is how it works:

extract html tags
    pass text further if condition is true
        do something and return
    return the text
put tags back and return

In python:

from typus.core import TypusCore
from typus.processors import BaseProcessor, EscapeHtml

class MyTrimProcessor(BaseProcessor):
    def run(self, text, **kwargs):
        # When processor is initiated it gets typus instance
        # as the first argument so you can access to it's configuration
        # any time
        if self.typus.trim:
            trimmed = text.strip()
            trimmed = text
        return self.run_other(trimmed, **kwargs)

class MyTypus(TypusCore):
    # This becomes a single function. EscapeHtml goes first
    processors = (EscapeHtml, MyTrimProcessor)

    # Set it to `False` to disable trimming
    trim = True

my_typus = MyTypus()
assert my_typus('    test    ') == 'test'

Built-in processors