Built-in Checkers

# Variable analysis
import pylint.checkers.variables
# - Unused variables and imports
# - Undefined variables
# - Variable redefinition
# - Global variable usage

# Import analysis  
import pylint.checkers.imports
# - Import order and grouping
# - Circular imports
# - Unused imports
# - Relative import usage

# Basic code analysis
import pylint.checkers.base
# - Unreachable code
# - Dangerous default arguments
# - Lost exception context
# - Assert statements on tuples

# Format and style checking
import pylint.checkers.format
# - Line length limits
# - Indentation consistency  
# - Trailing whitespace
# - Blank line usage
# - Operator spacing

# Method and function arguments
import pylint.checkers.method_args
# - Duplicate argument names
# - Missing required arguments
# - Keyword argument validation
# - *args and **kwargs usage

# Type checking and inference
import pylint.checkers.typecheck
# - Attribute access validation
# - Method call validation
# - Type compatibility checking
# - Iterator and sequence validation

# String usage analysis
import pylint.checkers.strings
# - String formatting validation
# - Quote consistency
# - String concatenation patterns
# - Format string validation

# Class analysis
import pylint.checkers.classes
# - Method resolution order
# - Abstract method implementation
# - Class attribute access
# - Special method implementation

# New-style class features
import pylint.checkers.newstyle
# - Property usage
# - Descriptor validation
# - Metaclass usage
# - Class decoration

# Exception handling analysis
import pylint.checkers.exceptions
# - Bare except clauses
# - Exception hierarchy validation
# - Exception chaining
# - Finally clause usage
# - Exception message validation

# Design analysis
import pylint.checkers.design_analysis
# - Cyclomatic complexity
# - Class coupling metrics
# - Method/class size limits
# - Inheritance depth analysis
# - Interface segregation

# Refactoring opportunities
import pylint.checkers.refactoring
# - Simplifiable conditions
# - Unnecessary loops
# - Redundant code patterns
# - Boolean expression simplification
# - Consider using enumerate/zip

# Standard library validation
import pylint.checkers.stdlib
# - Deprecated standard library usage
# - Incorrect API usage patterns
# - Performance anti-patterns
# - Security concerns in stdlib usage

# Logging usage analysis
import pylint.checkers.logging
# - Logging format string validation
# - Logger configuration checking
# - Log level consistency
# - Logging performance patterns

# Async/await pattern analysis
import pylint.checkers.async_
# - Async function usage
# - Await expression validation
# - Async context manager usage
# - Async iterator patterns

# Threading and concurrency
import pylint.checkers.threading
# - Thread safety analysis
# - Lock usage patterns
# - Shared state validation
# - Race condition detection

# Unicode and encoding
import pylint.checkers.unicode
# - Encoding declaration validation
# - Unicode string handling
# - Character encoding issues

# Spelling validation
import pylint.checkers.spelling
# - Comment and docstring spelling
# - Variable name spelling
# - Configurable dictionaries
# - Technical term validation

# Code similarity analysis
import pylint.checkers.symilar
# - Duplicate code detection
# - Similar structure identification
# - Configurable similarity thresholds
# - Cross-file duplication checking

# Examples of convention messages:
# C0103: invalid-name - Name doesn't conform to naming convention
# C0111: missing-docstring - Missing module/class/function docstring  
# C0301: line-too-long - Line exceeds maximum length limit
# C0326: bad-whitespace - Wrong whitespace usage

# Examples of refactor messages:
# R0201: no-self-use - Method could be a function
# R0903: too-few-public-methods - Class has too few public methods
# R0913: too-many-arguments - Function has too many arguments
# R1705: no-else-return - Unnecessary else after return

# Examples of warning messages:
# W0613: unused-argument - Unused function argument
# W0622: redefined-builtin - Redefining built-in function
# W0703: broad-except - Catching too general exception
# W1203: logging-fstring-interpolation - Use lazy % formatting in logging

# Examples of error messages:
# E0601: used-before-assignment - Using variable before assignment
# E1101: no-member - Instance has no member
# E1120: no-value-for-parameter - No value provided for required parameter
# E1136: unsubscriptable-object - Value is not subscriptable

# Examples of fatal messages:
# F0001: fatal - Error occurred preventing further processing
# F0010: error - Error in configuration or parsing
# F0202: method-check-failed - Unable to check method signature

from pylint.lint import PyLinter

linter = PyLinter()

# Disable specific checkers
linter.config.disable = ['missing-docstring', 'invalid-name']

# Enable only specific categories
linter.config.disable = 'all'
linter.config.enable = ['error', 'fatal']

# Configure specific checker options
linter.config.max_line_length = 120
linter.config.good_names = ['i', 'j', 'k', 'x', 'y', 'z']

# Configure variable naming patterns
linter.config.variable_rgx = r'[a-z_][a-z0-9_]{2,30}$'
linter.config.const_rgx = r'(([A-Z_][A-Z0-9_]*)|(__.*__))$'
linter.config.class_rgx = r'[A-Z_][a-zA-Z0-9]+$'

# Configure complexity limits
linter.config.max_complexity = 10
linter.config.max_args = 5
linter.config.max_locals = 15
linter.config.max_branches = 12

# Configure import checking
linter.config.import_graph = True
linter.config.ext_import_graph = True
linter.config.int_import_graph = True

# Filter messages by category
def filter_messages(message):
    # Only show errors and fatals
    return message.category in ['E', 'F']

# Filter messages by pattern
import re
def filter_by_pattern(message):
    # Skip messages about test files
    return not re.search(r'test_.*\.py', message.path)

# Variable naming and usage configuration
variable_rgx = r'[a-z_][a-z0-9_]{2,30}$'  # Variable name pattern
const_rgx = r'(([A-Z_][A-Z0-9_]*)|(__.*__))$'  # Constant pattern
good_names = ['i', 'j', 'k', 'x', 'y', 'z']  # Accepted short names
bad_names = ['foo', 'bar', 'baz']  # Forbidden names

# Import analysis configuration
deprecated_modules = ['optparse', 'imp']  # Modules to flag as deprecated
import_graph = True  # Generate import dependency graph
ext_import_graph = True  # Include external dependencies
preferred_modules = {'collections': 'collections.abc'}  # Preferred imports

# Code formatting configuration
max_line_length = 100  # Maximum line length
indent_string = '    '  # Indentation string (4 spaces)
indent_after_paren = 4  # Indentation after parenthesis
single_line_if_stmt = False  # Allow single-line if statements
single_line_class_stmt = False  # Allow single-line class statements