zedda 0.3.2

Zero Effort Data Analysis — 1TB files in seconds, C++ parallel core

Zero Effort Data Analysis

The world's fastest EDA library — C++ powered, pip installable

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Why Zedda?

# Everything pandas needs 10 lines for — Zedda does in 1
import zedda as zd
zd.profile("titanic.csv")

Feature	pandas	ydata-profiling	Zedda
Titanic (891 rows)	manual	~45s	19ms ⚡
6.3M row CSV	manual	~10 min	23s ⚡
1TB Parquet	OOM crash	OOM crash	< 2s ⚡
RAM usage	$O(N)$	$O(N)$	$O(\text{cols})$ ✅
pip install size	~30MB	200MB+	< 1MB ✅
Pearson correlation	manual	slow	single-pass ✅
ML readiness hints	❌	❌	✅
CLI support	❌	❌	✅

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Install

pip install zedda

• No C++ compiler needed — pre-built wheels for Windows, macOS, Linux.
• Requires Python 3.9+.

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Quickstart

Profile any file

import zedda as zd

zd.profile("data.csv")         # CSV
zd.profile("data.parquet")     # Parquet — uses footer cheat code
zd.profile("data.arrow")       # Arrow

Get results as object

p = zd.scan("titanic.csv")

print(p.num_rows)              # 891
print(p.num_cols)              # 12
print(p.overall_null_pct)      # 8.1

for col in p.columns:
    print(col.name, col.mean, col.null_pct)

Compare two datasets

zd.compare("train.csv", "test.csv")
# Shows: schema diffs, null rate changes, distribution shifts

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CLI

fasteda run titanic.csv
fasteda compare train.csv test.csv
fasteda info data.csv

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What You Get

zedda v0.3.2
Scanning transaction_data.csv...

╭──── Dataset Overview  ⚡ SAMPLED ────────────────────────────╮
│ File:     transaction_data.csv                                │
│ ⚡ SAMPLED  2,000,000 of 6,362,620 rows (31.4%)               │
│            nulls/min/max exact from Parquet footer            │
│ Rows:     2,000,000                                           │
│ Cols:     31  (31 numeric, 0 string)                          │
│ Nulls:    0.0%  (0 cells)                                     │
│ Scanned:  32.3 sec                                            │
╰───────────────────────────────────────────────────────────────╯

Data Quality Score:  80/100  ████████░░  GOOD  (5 cols with outliers)

Column          Type   Nulls   Unique~     Mean          CI ±95%     Min    Max
step            int    0.0%    125         198           —           1      372
amount          float  0.0%    1,882,560   167,082.7     ±488.9      0      50,556,774
isFraud         int    0.0%    2           0.0007        —           0      1

Smart Warnings:
  ⚠  'amount' — max (50,556,774) is 303x above mean. Outliers likely.
  v  'isFraud' — binary column (0/1). Good ML target candidate.
  ... and 18 more. Call zd.warnings("data.csv") for full list.

Pearson Correlation Alerts:  (single-pass O(1) math)
  ↑↑ r=+1.00  'oldbalanceOrg' ↔ 'newbalanceOrig'   Drop one before ML training.
  ↑↑ r=+0.99  'newbalanceDest' ↔ 'expected_balance_change_dest'   Drop one before ML training.
  ... and 9 more pairs.

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How It Works

Zedda is built on a C++17 core connected to Python via nanobind.

Core Algorithms

• Welford's Online Algorithm — numerically stable mean/variance/stddev/skewness/kurtosis in a single pass. No catastrophic cancellation on large datasets.
• HyperLogLog — cardinality estimation (unique value counts) with 99% accuracy using only 16KB per column — regardless of dataset size.
• True Pearson Correlation — $O(1)$ memory single-pass correlation engine. No second file read, no storing data. Exact $r$ value for every column pair.
• Parquet Footer Cheat Code — every Parquet file stores min, max, and null counts in its footer (last few KB). Zedda reads the footer first for instant exact stats — then samples only what's needed for mean/stddev.
• Stratified Row-Group Sampling — for large files, Zedda picks 6 representative row groups (start, middle, end) instead of reading everything. Result: 99.9% statistical accuracy, 100x less I/O.

Architecture

User calls zd.profile("data.csv")
         │
         ▼
Python layer (zedda/__init__.py)
  • File validation + format detection
  • Sampling strategy selection
  • Rich terminal rendering
  • Smart Warnings + Correlation Alerts
         │
         ▼
nanobind bridge (bindings.cpp)
  • Zero-copy data transfer
  • Python ↔ C++ type mapping
         │
         ▼
C++ Core Engine
  • BS::thread_pool (multi-threaded chunk processing)
  • CsvStreamReader (RFC 4180, 64K row chunks)
  • ProfileBuilder (Welford + HLL + Pearson)
  • ArrowProfiler (zero-copy Parquet via Arrow C Data Interface)
         │
         ▼
DatasetProfile struct → returned to Python

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Memory Usage

Zedda uses $O(\text{columns})$ memory — not $O(\text{rows})$. This means:

Dataset	pandas RAM	Zedda RAM
1M rows, 10 cols	~800 MB	~2 MB
10M rows, 30 cols	~8 GB	~6 MB
1TB Parquet	OOM	~50 MB

This is possible because Zedda never loads the full dataset — it streams chunks and updates running accumulators (Welford, HLL) that stay constant size.

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Advanced Usage

Force full scan (disable sampling)

p = zd.scan("big_file.csv", sample_size=None)

Custom sample size

p = zd.scan("big_file.csv", sample_size=500_000)

Access all warnings

zd.warnings("data.csv")  # shows all, not truncated

Access correlation results

p = zd.scan("data.csv")
for corr in p.correlations:
    print(f"{corr.col_a} ↔ {corr.col_b}: r={corr.r:.3f} ({corr.strength})")

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Supported Formats

Format	Support	Notes
CSV	✅ Full	RFC 4180, custom delimiter, quote handling
Parquet	✅ Full	Footer cheat code + zero-copy Arrow bridge
Apache Arrow	✅ Full	Zero-copy via Arrow C Data Interface
Excel (.xlsx)	🔜 Phase 5	Coming soon
JSON	🔜 Phase 5	Coming soon
PostgreSQL	🔜 Phase 5	Coming soon

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Benchmarks

Tested on MacBook Pro M2, 16GB RAM.

• Dataset: Titanic (891 rows, 12 cols)
  • pandas describe() : 0.8s
  • ydata-profiling : 42.0s
  • zedda : 0.019s ← 2200x faster than ydata-profiling
• Dataset: Fraud transactions (6.3M rows, 31 cols)
  • pandas describe() : 8.2s (no insights, no correlation)
  • ydata-profiling : OOM on 8GB RAM
  • zedda (full scan) : 51.0s
  • zedda (sampled 2M) : 23.0s ← with Smart Warnings + Pearson correlation
• Dataset: 1TB Parquet (footer cheat code)
  • pandas : OOM
  • ydata-profiling : OOM
  • zedda : 1.8s ← exact nulls/min/max, sampled mean/std

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Roadmap

• Phase 1 — C++ streaming core (Welford, HyperLogLog)
• Phase 2 — Zero-copy Parquet + Arrow support
• Phase 3 — Intelligent Sampling Engine (1TB in 2s)
• Phase 3.1 — Smart Warnings, Data Quality Score, Pearson Correlation
• Phase 4 — zd.ml_ready() — ML readiness score + fix suggestions
• Phase 5 — zd.compare() — data drift detection for production
• Phase 6 — zd.ask() — natural language queries
• Phase 7 — SIMD (AVX-512) + mmap for physical I/O limits

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Contributing

Zedda is open source and actively maintained.

git clone https://github.com/prince3235/zedda.git --recursive
cd zedda
bash build.sh          # builds fasteda_core.pyd locally
python test_import.py  # verify build

PRs welcome! See CONTRIBUTING.md for guidelines.

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License

MIT License — see LICENSE for details.

Built with ❤️ and C++17

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