Searching in Strings

Concepts covered: pyStringMethods

Python provides several ways to search for substrings within a string. Each method has specific use cases. The in Operator The first returns True (@ is in the email). The second returns False (gmail is not). find() and index() This finds @ at position 4, then searches for . starting from position 4, finding it at position 12. The count() Method This returns 3 (three a's), 2 (two "na" occurrences), and 0 (no x's). startswith() and endswith() These methods check if a string begins or ends with a specific substring: These are commonly used for file type validation, URL checking, and prefix/suffix matching.

About This Interactive Section

This section is part of the Strings: Intermediate lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

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