Pattern Searching Algorithms 📚

Pattern searching algorithms are essential tools in computer science and data processing. These algorithms are designed to efficiently find a particular pattern within a larger set of data.

✨ Features

📦 Installation

Option 1: From PyPI (Recommended) 🎉

pip install pattern-searching

Option 2: From GitHub (Development)

git clone https://github.com/HADIL19/Pattern-Searching.git
cd Pattern-Searching
pip install -e .

🚀 Quick Start

Single Pattern Search

from algorithms.single_pattern import boyer_moore_search
text = "The quick brown fox jumps over the lazy dog"
pattern = "fox"
boyer_moore_search(text, pattern)
# Output: Pattern found at index 16

Multiple Pattern Search

from algorithms.multiple_pattern import AhoCorasick
text = "Python is great. Java is powerful. C++ is fast."
patterns = ["Python", "Java", "C++"]
searcher = AhoCorasick(patterns)
searcher.search(text)
# Output:
# Pattern 'Python' found at index 0
# Pattern 'Java' found at index 17
# Pattern 'C++' found at index 34

🧬 Real-World Examples

DNA Sequence Analysis (Bioinformatics)

from algorithms.multiple_pattern import AhoCorasick
# Find restriction enzyme recognition sites in DNA
dna = "GAATTCGGATCCAAGCTT"
restriction_sites = ["GAATTC", "GGATCC", "AAGCTT"] # EcoRI, BamHI, HindIII
finder = AhoCorasick(restriction_sites)
finder.search(dna)
# Output:
# Pattern 'GAATTC' found at index 0 (EcoRI)
# Pattern 'GGATCC' found at index 6 (BamHI)
# Pattern 'AAGCTT' found at index 12 (HindIII)

Protein Motif Discovery

from algorithms.multiple_pattern import AhoCorasick
protein = "MVHLTPEEKSAVTALWGKVNVDEVGGEALGR"
motifs = ["VHL", "ALW", "GKV"]
finder = AhoCorasick(motifs)
finder.search(protein)

Content Filtering

from algorithms.multiple_pattern import AhoCorasick
forbidden_words = ["spam", "abuse", "inappropriate"]
filter_obj = AhoCorasick(forbidden_words)
user_comment = "This is spam content"
filter_obj.search(user_comment) # Detects forbidden content

📊 Algorithms Overview

Single-Pattern Algorithms

Multiple-Pattern Algorithms

🧩 Available Algorithms

Single-Pattern Algorithms

from algorithms.single_pattern import (
 naive_search, # Brute force - O(n×ばつm)
 boyer_moore_search, # Optimized - O(n/m)
 morris_pratt_search, # KMP variant - O(n+m)
 rabin_karp_search # Hash-based - O(n+m)
)

Multiple-Pattern Algorithms

from algorithms.multiple_pattern import (
 AhoCorasick, # Automaton-based ⭐
 rabin_karp_multiple, # Hash-based
 wu_manber, # Block-optimized
 commentz_walter # Boyer-Moore hybrid
)

📚 Documentation

🎯 Performance Comparison

Scenario: Long Text (2006 chars) with Pattern at End
Boyer-Moore ████░░░░░░ 82 μs ✅ FASTEST
Morris-Pratt ██████░░░░ 107 μs
Naive Search ████████░░ 147 μs
Rabin-Karp ███████████████ 344 μs
For Multiple Patterns (Single Pass):
Aho-Corasick ███░░░░░░░ BEST ⭐
Wu-Manber █████░░░░░
Commentz-Walter ██████░░░░

✅ Testing

✅ Naive Search - PASS
✅ Boyer-Moore - PASS
✅ Morris-Pratt - PASS
✅ Rabin-Karp - PASS
✅ Rabin-Karp (Multi) - PASS
✅ Aho-Corasick - PASS
✅ Wu-Manber - PASS
✅ Commentz-Walter - PASS
Status: ALL TESTS PASSING (7/7) ✅

📖 Usage Examples

Example 1: Find Keywords in Text

from algorithms.multiple_pattern import AhoCorasick
text = "Python is great. Java is powerful. Python is fun."
keywords = ["Python", "Java"]
searcher = AhoCorasick(keywords)
searcher.search(text)
# Finds all occurrences in a single pass!

Example 2: DNA Analysis

from algorithms.multiple_pattern import AhoCorasick
# Find genes in DNA sequence
gene_patterns = ["ATG", "TAA", "TAG", "TGA"] # Start and stop codons
dna_sequence = "ATGATGCGATAATAGCTAGATGATAG"
gene_finder = AhoCorasick(gene_patterns)
gene_finder.search(dna_sequence)

Example 3: Tandem Repeats

from algorithms.single_pattern import morris_pratt_search
# Find repeating sequences in DNA
dna = "AABAABAABAACAADAABAABA"
repeat = "AABA"
morris_pratt_search(dna, repeat) # Finds all overlapping repeats

Example 4: Case-Insensitive Search

from algorithms.single_pattern import boyer_moore_search
text = "Hello HELLO hello"
pattern = "hello"
# Convert to same case for search
boyer_moore_search(text.lower(), pattern.lower())

🎓 Educational Value

🌟 When to Use Each Algorithm

Single Pattern Search

Multiple Pattern Search

🔗 Related Topics

💻 Requirements

📁 Project Structure

Pattern-Searching/
├── README.md
├── LICENSE
├── setup.py
├── pyproject.toml
└── algorithms/
 ├── __init__.py
 ├── single_pattern/
 │ ├── __init__.py
 │ ├── naive.py
 │ ├── boyer_moore.py
 │ ├── morris_pratt.py
 │ └── rabin_karp.py
 └── multiple_pattern/
 ├── __init__.py
 ├── aho_corasick.py
 ├── rabin_karpe_pattern.py
 ├── wu_manber.py
 └── commentz_walter.py

🤝 Contributing

📝 Citation

@software{pattern_searching_2024,
 title={Pattern-Searching: String Searching Algorithms Library},
 author={HADIL19},
 year={2024},
 url={https://github.com/HADIL19/Pattern-Searching}
}

⚖️ License

🙋 Support & Questions

📊 Statistics

🎉 Getting Started

1. Install

pip install pattern-searching

2. Import

from algorithms.single_pattern import boyer_moore_search
from algorithms.multiple_pattern import AhoCorasick

3. Use

# Single pattern
boyer_moore_search("Hello World", "World")
# Multiple patterns
searcher = AhoCorasick(["Hello", "World"])
searcher.search("Hello World")

📚 More Information

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