Module cohesion 

Cohesion command - LCOM4 (Lack of Cohesion of Methods) analysis for Python classes.

LCOM4 measures class cohesion by counting connected components in the method-field graph:

• LCOM4 = 1: All methods are connected (cohesive class)
• LCOM4 > 1: Methods form disconnected groups (split candidate)

Algorithm

1. Parse class, extract methods and field accesses (self.x)
2. Build bipartite graph: methods <-> fields they access
3. Add edges for intra-class method calls (self.method())
4. Count connected components via union-find with path compression

TIGER Mitigations

• T06: Union-find with path compression AND union by rank
• E01: --timeout flag (default 30s)
• E04: MAX_METHODS_PER_CLASS and MAX_FIELDS_PER_CLASS limits
• E05: MAX_ITERATIONS for union-find operations

Example

tldr cohesion src/models.py
tldr cohesion src/models.py --min-methods 3 --include-dunder
tldr cohesion src/ --format text

Structs

CohesionArgs

Compute LCOM4 (Lack of Cohesion of Methods) metric for Python classes.

UnionFind

Union-Find (Disjoint Set Union) data structure with path compression and union by rank.

Enums

OutputFormat

Output format for cohesion command

Functions

format_cohesion_text

Format a cohesion report as human-readable text.

run

Run cohesion analysis (for programmatic use).