Should you be inside or outside Dataiku I think you should use the python API (accessible from a Dataiku notebook or using the python client library
import dataiku
import json
# Listing project datasets
myproject = client.get_project('YOUR_PROJECT_NAME')
datasets = project.list_datasets()
for datasetName in project.list_datasets():
# get dataset object
dataset = myproject.get_dataset(' batting_postseason')
# dump dataset schema
json.dumps(dataset.get_schema())
Since you can also install this client api outside DSS it's the most universal way to me but beware Dataiku also provide a catalog and public api call to index Dataiku connections and retrieve statistics on all your items including those not used in a project yet.
Edit :
There's also a plugin called "Audits a dataset" that allows you to generate quickly such a report without coding.