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From: Ben Finney <ben+python@benfinney.id.au>
Newsgroups: comp.lang.python
Subject: Validation in Python (was: raise None)
Date: Thu, 31 Dec 2015 11:26:14 +1100
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Steven D'Aprano <steve@pearwood.info> writes:

> I have a lot of functions that perform the same argument checking each
> time:

Not an answer to the question you ask, but: Have you tried the data
validation library “voluptuous”?

    Voluptuous, despite the name, is a Python data validation library.
    It is primarily intended for validating data coming into Python as
    JSON, YAML, etc.

    It has three goals:

        Simplicity.
        Support for complex data structures.
        Provide useful error messages.

    <URL:https://pypi.python.org/pypi/voluptuous/>

Seems like a good way to follow Don't Repeat Yourself in code that needs
a lot of validation of inputs.

-- 
 \     “It's my belief we developed language because of our deep inner |
  `\                  need to complain.” —Jane Wagner, via Lily Tomlin |
_o__)                                                                  |
Ben Finney