Python Pandas Library
Pandas is an open-source library for data analysis and manipulation in Python. It provides fast, flexible and expressive data structures for working with relational and labelled data. Originally developed by Wes McKinney in 2008, it has become a foundational tool in modern data science and serves as a highly programmable analogue to spreadsheet software. Key characteristics NumPy foundation: Built on top of NumPy, it inherits highly optimised, array-based computational performance. Label-driven alignment: Data are automatically aligned according to explicit row and column labels, thereby improving the reliability of calculations involving partially mismatched datasets. Heterogeneous typing: Unlike strict numerical arrays, Pandas can accommodate mixed data types, including integers, strings, floats and booleans, within a single tabular structure. Missing-data resilience: It provides native support for detecting, representing and handling missing values, such as NaN. Core data structures Series: A one-dimensional labelled array capable of holding any data type. In practical terms, it resembles a single column in a spreadsheet. DataFrame: A two-dimensional tabular data structure with labelled rows and columns. It may be regarded as a collection of Series sharing a common index, analogous to a table in SQL or a worksheet in Excel. Core features and capabilities Robust input/output parsing: Pandas supports efficient reading and writing across multiple formats, including CSV, Excel, SQL databases, JSON and Parquet. Advanced data cleaning: Built-in methods enable users to identify, filter and remove duplicates, and to impute missing values. Flexible wrangling and reshaping: The library facilitates pivoting, melting, slicing and subsetting operations based on conditional logic. High-performance merging: Relational operations such as inner, outer, left and right joins, as well as concatenation, can be executed in concise code. Split-apply-combine (GroupBy): Data may be group