Table of contents
The PaVal module is an easy-to-use parameter validator for methods inside Python scripts.
Before, there was some code to validate the given parameters (such as directory and file paths, numbers, ranges and strings) in many of my projects. This worked fine so far, but there was (partially the same) parameter validation code in various components.
So, if that code needed to be changed, it had to be done in various files of the project and (according to the significance of the change) also in other projects, which was sometimes pretty laborious.
Due to this, the common and non-project-specific parameter validation code has been exported from each project and merged in a single project independent module. In some cases it saved more than a hundred lines of code per project.
The module works read-only. This means, its methods validate the given values and raise an exception in case of an error, but they do not change or return anything.
The current version of PaVal comes with the following features.
Check a given path...
- if it exists.
- if it points to a directory or file.
Compare a file with a list of other files...
- to check if the same file name is given multiple times.
- to check if the file is given multiple times with a different name but the same content.
Check an integer value...
- if it is positive, zero or negative.
Check an integer range...
- if the given value is inside that range.
- if the given value is zero.
Check a string...
- if it contains wildcard characters.
- if it contains invalid characters (user-defined).
Compare a string with a list of other strings...
- to check if the string is an item of the list.
In order to run the latest version of PaVal, the Python 3.x framework (version 3.2 or higher is recommended) must be installed on the system.
Version 1.2.7 is the last release that officially supports the Python 2.x framework.
If you need a later version for the Python 2.x framework for whatever reason, you can try refactoring the syntax from Python 3.x to version 2.x using the 3to2 tool.
However, there is no guarantee that this works properly or at all.
You can find usage examples inside the example.py file.
Any suggestions, questions, bugs to report or feedback to give?
You can contact me by sending an email to dev@urbanware.org or by opening a GitHub issue (which I would prefer if you have a GitHub account).
- The project name is an abbreviation for Parameter Validator.
- The first version uploaded on GitHub was PaVal 1.2.5 built on February 11th, 2016.
- The module for Python 3 was initially created by converting the Python 2 module using the 2to3 tool. However, both files are identical except for the shebang.