nano_dev_utils

A collection of small Python utilities for developers. PYPI package: nano-dev-utils

Modules

timers.py

This module provides a Timer class for measuring the execution time of code blocks and functions with additional features like timeout control and multi-iteration averaging.

Timer Class

• __init__(self, precision: int = 4, verbose: bool = False, printout: bool = False): Initializes a Timer instance.

  • precision: The number of decimal places to record and display time durations. Defaults to 4.
  • verbose: Optionally displays the function's positional arguments (args) and keyword arguments (kwargs). Defaults to False.
  • printout: Allows printing to console.

• def timeit( self, iterations: int = 1, timeout: float | None = None, per_iteration: bool = False, ) -> Callable[[Callable[P, Any]], Callable[P, Any]]::
  Decorator that times either sync or async function execution with advanced features:

  • iterations: Number of times to run the function (for averaging). Defaults to 1.
  • timeout: Maximum allowed execution time in seconds. When exceeded:
    • Raises TimeoutError immediately
    • Warning: The function execution will be aborted mid-operation
    • No return value will be available if timeout occurs
  • per_iteration: If True, applies timeout check to each iteration; otherwise checks total time across all iterations.
  • Features:
    • Records execution times
    • Handles timeout conditions
    • Calculates average execution time across iterations
    • Logs the function name and execution time (with optional arguments)
    • Returns the result of the original function (unless timeout occurs)

Example Usage:

import time
import logging
from nano_dev_utils import timer

# if printout is not enabled, a logger must be configured in order to see timing results
logging.basicConfig(filename='timer example.log',
                    level=logging.INFO,  # DEBUG, WARNING, ERROR, CRITICAL
                    format='%(asctime)s - %(levelname)s: %(message)s',
                    datefmt='%d-%m-%Y %H:%M:%S')

# Basic timing
@timer.timeit()
def my_function(a, b=10):
    """A sample function."""
    time.sleep(0.1)
    return a + b

timer.init(precision=6, verbose=True)
'''Alternative options: 
timer.update({'precision': 6, 'verbose': True})  # 1. Using update method  

from nano_dev_utils.timers import Timer  # 2. explicit instantiation
timer = Timer(precision=6, verbose=True)  
'''

timer.update({'printout': True})  # allow printing to console

# Advanced usage with timeout and iterations
@timer.timeit(iterations=5, timeout=0.5, per_iteration=True)
def critical_function(x):
    """Function with timeout check per iteration."""
    time.sleep(0.08)
    return x * 2

result1 = my_function(5, b=20)  # Shows args/kwargs and timing
result2 = critical_function(10)  # Runs 5 times with per-iteration timeout

dynamic_importer.py

This module provides an Importer class for lazy loading and caching module imports.

Importer Class

• __init__(self): Initializes an Importer instance with an empty dictionary imported_modules to cache imported modules.

• import_mod_from_lib(self, library: str, module_name: str) -> ModuleType | Any: Lazily imports a module from a specified library and caches it.

  • library (str): The name of the library (e.g., "os", "requests").
  • module_name (str): The name of the module to import within the library (e.g., "path", "get").
  • Returns the imported module. If the module has already been imported, it returns a cached instance.
  • Raises ImportError if the module cannot be found.

Example Usage:

from nano_dev_utils import importer

os_path = importer.import_mod_from_lib("os", "path")
print(f"Imported os.path: {os_path}")

requests_get = importer.import_mod_from_lib("requests", "get")
print(f"Imported requests.get: {requests_get}")

# Subsequent calls will return the cached module
os_path_again = importer.import_mod_from_lib("os", "path")
print(f"Imported os.path again (cached): {os_path_again}")

release_ports.py

This module provides a PortsRelease class to identify and release processes listening on specified TCP ports.
It supports Windows, Linux, and macOS.

PortsRelease Class

• __init__(self, default_ports: list[int] | None = None):

• Initializes a PortsRelease instance.

  • default_ports: A list of default ports to manage. If not provided, it defaults to [6277, 6274].

• get_pid_by_port(self, port: int) -> int | None: A static method that attempts to find
  a process ID (PID) listening on a given port.

• It uses platform-specific commands (netstat, ss, lsof).

• Returns the PID if found, otherwise None.

• kill_process(self, pid: int) -> bool: A static method that attempts to kill the process with the given pid.

• It uses platform-specific commands (taskkill, kill -9).

• Returns True if the process was successfully killed, False otherwise.

• release_all(self, ports: list[int] | None = None) -> None: Releases all processes listening on the specified ports.

  • ports: A list of ports to release.
  • If None, it uses the default_ports defined during initialization.
  • For each port, it first tries to get the PID and then attempts to kill the process.
  • It logs the actions and any errors encountered. Invalid port numbers in the provided list are skipped.

Example Usage:

import logging
from nano_dev_utils import ports_release, PortsRelease

 
logging.basicConfig(filename='port release.log',
                    level=logging.INFO,  # DEBUG, WARNING, ERROR, CRITICAL 
                    format='%(asctime)s - %(levelname)s: %(message)s',
                    datefmt='%d-%m-%Y %H:%M:%S')


ports_release.release_all()

# Create an instance with custom ports
custom_ports_releaser = PortsRelease(default_ports=[8080, 9000, 6274])
custom_ports_releaser.release_all(ports=[8080, 9000])

# Release only the default ports
ports_release.release_all()

License

This project is licensed under the MIT License. See LICENSE for details.