Python for Data Analysis Questions

Covers the practical use of Python and its data libraries to perform data ingestion, cleaning, transformation, analysis, and aggregation. Candidates should be able to manipulate data frames, perform complex grouping and aggregation operations, merge and join multiple data sources, and implement efficient vectorized operations using libraries such as Pandas and NumPy. Expect to write clear, idiomatic Python with appropriate error handling, input validation, and small tests or assertions. At more senior levels, discuss performance trade offs and scalability strategies such as choosing NumPy vectorization versus Pandas, and when to adopt alternative tools like Polars or Dask for very large datasets, as well as techniques for memory management, profiling, and incremental or streaming processing. Also cover reproducibility, serialization formats, and integrating analysis into pipelines.