Decorators for Humans

The goal of the decorator module is to make it easy to define signature-preserving function decorators and decorator factories. It also includes an implementation of multiple dispatch and other niceties (please check the docs). It is released under a two-clauses BSD license, i.e. basically you can do whatever you want with it but I am not responsible.

Installation

If you are lazy, just perform

$ pip install decorator

which will install just the module on your system.

If you prefer to install the full distribution from source, including the documentation, clone the GitHub repo_ or download the tarball_, unpack it and run

$ pip install .

in the main directory, possibly as superuser.

Testing

If you have the source code installation you can run the tests with

$ python tests/test.py -v

Notice that you may run into trouble if in your system there is an older version of the decorator module; in such a case remove the old version. It is safe even to copy the module decorator.py over an existing one, since we kept backward-compatibility for a long time.

Repository

The project is hosted on GitHub. You can look at the source here:

https://github.com/micheles/decorator

Documentation

The documentation has been moved to https://github.com/micheles/decorator/blob/master/docs/documentation.md

From there you can get a PDF version by simply using the print functionality of your browser.

Here is the documentation for previous versions of the module:

https://github.com/micheles/decorator/blob/4.3.2/docs/tests.documentation.rst https://github.com/micheles/decorator/blob/4.2.1/docs/tests.documentation.rst https://github.com/micheles/decorator/blob/4.1.2/docs/tests.documentation.rst https://github.com/micheles/decorator/blob/4.0.0/documentation.rst https://github.com/micheles/decorator/blob/3.4.2/documentation.rst

For the impatient

Here is an example of how to define a family of decorators tracing slow operations:

from decorator import decorator

@decorator
def warn_slow(func, timelimit=60, *args, **kw):
    t0 = time.time()
    result = func(*args, **kw)
    dt = time.time() - t0
    if dt > timelimit:
        logging.warning('%s took %d seconds', func.__name__, dt)
    else:
        logging.info('%s took %d seconds', func.__name__, dt)
    return result

@warn_slow  # warn if it takes more than 1 minute
def preprocess_input_files(inputdir, tempdir):
    ...

@warn_slow(timelimit=600)  # warn if it takes more than 10 minutes
def run_calculation(tempdir, outdir):
    ...

Enjoy!