Parse a fixed-width mainframe extract

Python data engineering interview problem. Difficulty: intermediate. Pattern: Strings. About 15 minutes. Part of the Pro drill bank.

A nightly mainframe extract is fixed-width, not CSV. Each field lives in character positions defined by a spec. You must slice, not split on commas.

Parse fixed-width lines using the provided field spec.

Requirements

• Slice each line by the spec widths in order.
• Strip padding as the tests require.

Constraints

• lines: raw extract rows.
• spec: field name to width (or start/end) mapping.
• Short lines should follow the spec (pad vs skip).
• Keep one output record per input line.

Examples

Input: parse_fixed_width(['SKU1widget'], [('sku', 0, 4), ('name', 4, 6)]) Output: [{'sku': 'SKU1', 'name': 'widget'}] This input follows the stated rules and produces this output.

Topics: lakebench, python, file/data-processing.

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