How to connect to data on S3 using Pandas
This guide will help you connect to your data stored on AWS S3 using Pandas. This will allow you to ValidateThe act of applying an Expectation Suite to a Batch. and explore your data.
Prerequisites: This how-to guide assumes you have:
- Completed the Quickstart guide
- A working installation of Great Expectations
- Have access to data on an AWS S3 bucket
Steps
1. Choose how to run the code in this guide
Get an environment to run the code in this guide. Please choose an option below.
- CLI + filesystem
- No CLI + filesystem
- No CLI + no filesystem
If you use the Great Expectations CLICommand Line Interface, run this command to automatically generate a pre-configured Jupyter Notebook. Then you can follow along in the YAML-based workflow below:
great_expectations datasource new
If you use Great Expectations in an environment that has filesystem access, and prefer not to use the CLICommand Line Interface, run the code in this guide in a notebook or other Python script.
If you use Great Expectations in an environment that has no filesystem (such as Databricks or AWS EMR), run the code in this guide in that system's preferred way.
2. Instantiate your project's DataContext
Import these necessary packages and modules.
import great_expectations as gx
from great_expectations.core.batch import Batch, BatchRequest, RuntimeBatchRequest
from great_expectations.core.yaml_handler import YAMLHandler
yaml = YAMLHandler()
Load your DataContext into memory using the get_context()
method.
context = gx.get_context()
3. Configure your Datasource
Using this example configuration, add in your S3 bucket and path to a directory that contains some of your data:
datasource = context.sources.add_or_update_pandas_s3(
name="s3_datasource", bucket="taxi-data-sample-test"
)
In the example, we have added a Datasource that connects to data in S3 using a Pandas dataframe. The name of
the new datasource is s3_datasource
and it refers to a S3 bucket named taxi-data-sample-test
.
4. Save the Datasource configuration to your DataContext
Save the configuration into your DataContext
by using the add_datasource()
function.
- YAML
- Python
context.add_datasource(**yaml.load(datasource_yaml))
context.add_datasource(**datasource_config)
5. Test your new Datasource
Verify your new DatasourceProvides a standard API for accessing and interacting with data from a wide variety of source systems. by loading data from it into a ValidatorUsed to run an Expectation Suite against data. using a Batch RequestProvided to a Datasource in order to create a Batch..
We will use the BatchRequest
configured in the previous step.
context.add_or_update_expectation_suite(expectation_suite_name="test_suite")
validator = context.get_validator(
batch_request=request, expectation_suite_name="test_suite"
)
print(validator.head())
🚀🚀 Congratulations! 🚀🚀 You successfully connected Great Expectations with your data.
Additional Notes
Next Steps
Now that you've connected to your data, you'll want to work on these core skills: