FabGuard

FabGuard is a tool that helps verify input files by specifying constraints on input data. This is a first iteration where we are collecting the type of constraints in various simulation input files and deriving the tool requirements. As a first exercise, we are testing a library for data validation of Panda Dataframes, called pandera.

Installation

To install FabGuard, follow these steps:

1. Clone the FabGuard repository:

2. Install the required dependencies:

pip install pandera

Test examples

1. Test the examples in the test_pandera.py file to familiarise yourself with the capabilities of the library. test_pandera.py demonstrates how to test three type of constraints:

• simple constraints on columns. The function below can check the following simple constraint:
  • population > 0
  • location_type shouldhave one of the following values "conflict_zone", "town", "camp", "forwarding_hub"

  def validate_simple_constraints():
      schema = pa.DataFrameSchema(
          {
              "population": Column(float, Check.greater_than(10), nullable=True),
              "location_type": Column(str, Check.isin(["conflict_zone", "town", "camp", "forwarding_hub"])),
          }
      )
  
      return schema 

• constraints spanning multiple columns from the same file The function below can check the following constraint using a lambda function:
  • if location_type == "conflict_zone" then population > 0

  def validate_two_dependent_columns():
      schema = pa.DataFrameSchema(
          {
              "population": pa.Column(float, [
                  pa.Check(
                      lambda g: g["conflict_zone"] > 0,
                      groupby=["location_type"])], nullable=True, coerce=True),
              "location_type": Column(str, Check.isin(["conflict_zone", "town", "camp", "forwarding_hub"])),
          }
      )
  
      return schema 

• constarints spanning multiple files

2. You can check other examples in test_pandera.py

How-to: Test on your own dataset:

1. Define a verify function that returns a pandera schema Examples of such functions are the functions given in the Test examples section validate_simple_constraints

2 Call the validator.validate function with the above function and the data frame to be verified:

dfs = util.load_files(["test_data/locations.csv", "test_data/closures.csv"])
validator.validate(validate_simple_constraints, dfs["closures"], "verify_multi.yaml")

where

• util.load_files reads the list of files and returns a dictionary of dataframes
• validator.validatetakes a validation function, a dataframe, and a yaml output file

List of requirements

• metrics across different runs

• count function on columns: the value of one column should be the size of a column in one file should be

  • conflict_period.length = size(closures.day)

• ✓ All cities in location.csv should have routes in routes.csv (location.name should be in routes.name1 or routes.name2)

  • If locations.location_type == camp then location.name in routes.name1 or location.name is routes.name2

• ✓ The number of records in location_type is X then data_laypout file contains a linked record:

  • if location.location_type == camp then
    • Location.name in data_layout.total and data_layout.name is nonempty.

• All columns but one should satisfy the same constraint

• ✓ All data exists, min-max, All regions have positive values

• Check scheme (such that yaml does not break w.r.t identation)