pandas-slim 0.1.2

A Python library to reduce pandas DataFrame memory usage

🚀 pandas-slim

A high-performance Python library for dramatically reducing pandas DataFrame memory usage through intelligent optimization techniques.

🎯 Why pandas-slim?

Pandas DataFrames can consume massive amounts of memory, especially with large datasets. pandas-slim provides scientifically-tested memory optimization techniques that can reduce your DataFrame memory usage by up to 87% while maintaining data integrity.

📦 Installation

pip install pandas-slim

⚡ Quick Start

import pandas as pd
from pandas_slim import reduce_mem_usage
from sklearn.datasets import load_wine

# Load your DataFrame
df = pd.DataFrame(load_wine().data, columns=load_wine().feature_names)
print(f"Original memory: {df.memory_usage().sum() / 1024**2:.2f} MB")

# Reduce memory usage with one line!
df_optimized = reduce_mem_usage(df)
# Output: Memory usage decreased by 75.4%!

🧪 Scientific Benchmark Results

We tested 7 different optimization methods on the sklearn wine dataset. Here are the results:

🏆 Performance Summary

Method	Memory Reduction	Speed	Best For
🥇 Quantized	86.9%	0.0024s	Maximum compression
🥈 Advanced (User v1)	75.4%	0.0446s	Balanced optimization
🥉 Aggressive	75.4%	0.0023s	Fast & effective
Basic	74.5%	0.0010s	Quick optimization
Sparse Matrix	74.5%	0.0022s	Sparse data
Precision Loss (16-bit)	74.5%	0.0009s	Fastest method
Precision Loss (8-bit)	74.5%	0.0009s	Ultra-fast

📊 Detailed Benchmark

Key Findings:

• 🎯 Quantized method achieved the highest memory reduction at 86.9%
• ⚡ Precision Loss (16-bit) was the fastest with 0.0009s execution time
• 🏅 Most efficient method: Precision Loss (16-bit) with efficiency score of 81,107.7
• 📈 All methods successfully reduced memory usage by 74.5% or more

🔧 Features

Multiple Optimization Strategies

1. Basic Optimization

from pandas_slim import MemoryOptimizer

optimizer = MemoryOptimizer(strategy='basic')
df_basic = optimizer.optimize(df)

2. Advanced Optimization (Recommended)

from pandas_slim import reduce_mem_usage

# Smart integer detection and unsigned integer usage
df_advanced = reduce_mem_usage(df, int_cast=True, obj_to_category=False)

3. Aggressive Optimization

optimizer = MemoryOptimizer(strategy='aggressive')
df_aggressive = optimizer.optimize(df)

Scientific Benchmarking

from pandas_slim import MemoryOptimizer

optimizer = MemoryOptimizer()

# Get detailed benchmark results
results = optimizer.benchmark(df)
print(results)

# Create visualization
optimizer.plot_benchmark(df, save_path='benchmark.png')

📊 Benchmark Results

Here's how different optimization methods perform on the Wine dataset:

Results show memory reduction percentage and execution time for each optimization method.

🧠 How It Works

pandas-slim uses several intelligent techniques to reduce memory usage:

1. Intelligent Downcasting: Automatically selects the smallest possible numeric dtype that can hold your data
2. Smart Integer Detection: Identifies float columns that can be safely converted to integers
3. Unsigned Integer Optimization: Uses unsigned integers when all values are positive
4. Category Conversion: Converts repetitive string data to memory-efficient category dtype
5. Float Precision Optimization: Reduces float precision when possible without data loss

Supported Data Types

Original Type	Optimized Options
int64	int8, int16, int32, uint8, uint16, uint32
float64	float16, float32, or convert to integer
object	category (optional)

📚 API Reference

reduce_mem_usage(df, int_cast=True, obj_to_category=False, subset=None, verbose=True)

Main function to reduce DataFrame memory usage.

Parameters:

• df (pd.DataFrame): DataFrame to optimize
• int_cast (bool): Try to convert float columns to integers when possible
• obj_to_category (bool): Convert object columns to category dtype
• subset (list): Specific columns to optimize (default: all columns)
• verbose (bool): Print optimization progress and results

Returns:

• pd.DataFrame: Optimized DataFrame

MemoryOptimizer(strategy='advanced')

Class-based interface for memory optimization.

Methods:

• optimize(df, **kwargs): Optimize DataFrame using selected strategy
• benchmark(df): Compare all optimization methods
• plot_benchmark(df, save_path=None): Visualize benchmark results

🎯 Use Cases

• Large Dataset Processing: Reduce memory usage for big data analysis
• Machine Learning Pipelines: Optimize feature matrices before training
• Data Warehousing: Compress data for storage and transfer
• Memory-Constrained Environments: Maximize available RAM usage
• Performance Optimization: Speed up operations on large DataFrames

🔬 Scientific Approach

pandas-slim is built with a scientific mindset:

• Benchmarking: Built-in tools to measure and compare optimization methods
• Reproducibility: Consistent results across different datasets
• Validation: Extensive testing to ensure data integrity
• Transparency: Clear reporting of memory savings and processing time

🤝 Contributing

We welcome contributions! Please see our Contributing Guidelines for details.

1. Fork the repository
2. Create a feature branch
3. Add tests for your changes
4. Submit a pull request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Inspired by the excellent work at mikulskibartosz.name
• Built with ❤️ for the data science community

📈 Performance Tips

1. Use int_cast=True for datasets with float columns that might be integers
2. Enable obj_to_category=True for datasets with repetitive string data
3. Process in chunks for extremely large datasets
4. Benchmark first to choose the best strategy for your specific data

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Made with 🔥 by Remi Ounadjela

Reduce your data, amplify your insights!