Usage examples / recipes

In these pages we try to provide real-world examples so that you may find an answer for most common validation tasks, according to your coding style (several are proposed). Feel free to propose some examples through a git issue or pull request!

Common imports

In all examples, we use numbers.Integral rather than int so as to support both python primitive int and other compliant types such as numpy int. The same goes for numbers.Real and valid8.Boolean (yes, unfortunately such an equivalent boolean type is not provided by the stdlib).

from numbers import Integral, Real
from valid8 import Boolean

Examples list

• Example 1: x is a positive integer. This is the most simple example.
• Example 2: s is a lowercase non-empty string. In this example we start to see the limits of built-in functions and parameters, but are still able to find workarounds without writing custom functions.
• Example 3: t is a custom tuple. In this example it becomes clearly easier/more readable to write a custom function and use it in the validation tools
• Example 4: l is a list of custom tuples. This is to demonstrate iterative validation on container objects.
• Example 5: df is a dataframe containing specific columns
• Example 6: x and y should be such that either x is A or B and y is None, or x is C and y is a positive integer. This example demonstrates how to use the validation tools for combination of variables (TODO)

Note: we deliberately do not use any help_msg or error_type customization in any of the examples to focus on the validation core. See here for details on how to customize these examples.