Custom Data Analysis Library

Immutability mirrors professional quant libraries and helps prevent subtle mutation bugs. A Column wraps a Vector with a string name and provides arithmetic, statistics, and shift operations. The custom Vector class wraps a NumPy array and overloads arithmetic operators to demonstrate vectorized mechanics. Every Vector arithmetic operation creates a new array rather than modifying the original in place. The custom DataFrame stores an ordered list of columns in a column-major layout matching pandas and Polars memory organization.