CSV Parser & Analyzer

A command-line tool that reads CSV files and lets you explore the data interactively — filter, sort, get stats, group and count, and export the results. Think of it as a tiny Excel for your terminal.

Features

• Load any CSV file
• Display data as a clean, aligned table
• Filter by exact match or by numeric range
• Sort ascending/descending, alphabetically or numerically
• Statistics: min, max, average, median
• Group and count values in a column
• Export the current working set to a new CSV
• Interactive menu-driven CLI, with a reset option to undo filters/sorts

Quick start

cd src
javac *.java
java Main

Then follow the menu prompts — load a CSV, then filter, sort, analyze, or export it.

=== CSV Analyzer ===
1. Load CSV file
2. Display data
3. Filter data
4. Sort data
5. Show statistics
6. Group and count
7. Export data
8. Exit
9. Reset

Example workflow

1. Load sample.csv
2. Filter for age in range 25–100
3. Sort by rating, descending
4. Export the result to filtered_results.csv

How it's organized

Class	Responsibility
Record	One row of data — a String[] of values plus a shared column-name → index map, so any value can be looked up by name (getValueByName("age")) instead of by position
CSVReader	Reads a file into a header array and a list of Records
Display	Pretty-prints the current data as a padded, aligned table
Filter	Returns a new list of records matching an exact value or falling within a numeric range
Sorter	Sorts a list of records by a given column, ascending or descending (bubble sort; numeric if the column parses as a number, lexicographic otherwise)
Stats	Computes min, max, average, and median for a numeric column
GroupBy	Counts how many records share each distinct value in a column
Exporter	Writes the current headers + records back out to a CSV file

Main ties everything together as a menu loop: it keeps track of the original records and a workingSet that filters/sorts get applied to, so you can chain operations (filter, then sort, then export) without reloading the file, and reset back to the original data at any point.

Challenges along the way

• Keeping track of an ArrayList of Records that each wrap a String[] — lists of objects wrapping arrays got confusing fast.
• Sorting a list of Record objects without quietly sorting shared references — Sorter deep-copies each Record before sorting so the original workingSet/records lists are never mutated underneath you.
• First real use of BufferedReader/BufferedWriter and FileReader/FileWriter for file I/O.
• Getting comfortable with HashMaps for the column-name lookups, and string utilities like String.join and String.format for clean output.

Possible next steps

• A simple GUI instead of the CLI menu
• Support for combining multiple filter conditions at once
• A faster sort than bubble sort for larger files