Data apps are interactive apps, built in single-file Python scripts, to run on Peliqan. This page provides a Reference for building Data apps.

Data apps on the Peliqan platform

Peliqan is an all-in-one data platform with a wide range of components, that can be controlled and used from within Data apps using Peliqan’s pq module:

• Connectors (ETL pipelines that sync data from sources into a datawarehouse)
• Built-in datawarehouse, and ability to connect an external datawarehouse as ETL target
• Data explorer & SQL queries for data transformations (queries can be configured as views and/or can be materialized)
• Trino federated query engine
• Data replication
• Python IDE and runtime to develop, test, host, schedule & publish Data apps

Peliqan pq module

The pq module exposes Peliqan’s low-code data-centric and data pipeline functions. The pq module is automatically available in Peliqan when you write Python code in Data apps and can be used in your local IDE by doing pip install peliqan and using import peliqan as pq in your code.

Constants

pq.DW_NAME       # Name of default data warehouse (database) in the current account, also name of the default data warehouse connection
pq.DW_ID         # Id of default data warehouse in the current account
pq.INTERFACE_ID  # Current script id
RUN_CONTEXT      # Possible values: interactive, scheduled, api_handler or not set (outside of Peliqan)

# Example detect if script running inside or outside of Peliqan:

if 'RUN_CONTEXT' not in globals():
	print("Running outside of Peliqan)

Run modes

Data apps can run locally on a computer (external to Peliqan) or inside the Peliqan platform.

When hosted on Peliqan, some code is prepended, e.g. to provide context and to automatically import Streamlit as st and Peliqan as pq.

Constant RUN_CONTEXT is always set when running a Data app in Peliqan.

Data apps can run interactively or in the background (e.g. scheduled). Streamlit is used to build UI’s for interactive apps.

Streamlit functions such as st.text(), st.write(), st.json(), st.table() etc. are converted to print statements in background runs.

Print statements are written to the log file of each run, visible in Peliqan.