stouputils.parallel module#

This module provides utility functions for parallel processing, such as:

  • multiprocessing(): Execute a function in parallel using multiprocessing

  • multithreading(): Execute a function in parallel using multithreading

I highly encourage you to read the function docstrings to understand when to use each method.

stouputils parallel examples
__handle_parameters(func: Callable[[T], R], args: list[T], use_starmap: bool, delay_first_calls: float, max_workers: int, desc: str, color: str) tuple[str, Callable[[T], R], list[T]][source]#

Private function to handle the parameters for multiprocessing or multithreading functions

Parameters:
  • func (Callable) – Function to execute

  • args (list) – List of arguments to pass to the function

  • use_starmap (bool) – Whether to use starmap or not (Defaults to False): True means the function will be called like func(*args[i]) instead of func(args[i])

  • delay_first_calls (int) – Apply i*delay_first_calls seconds delay to the first “max_workers” calls. For instance, the first process will be delayed by 0 seconds, the second by 1 second, etc. (Defaults to 0): This can be useful to avoid functions being called in the same second.

  • max_workers (int) – Number of workers to use (Defaults to CPU_COUNT)

  • desc (str) – Description of the function execution displayed in the progress bar

  • color (str) – Color of the progress bar

Returns:

Tuple containing the description, function, and arguments

Return type:

tuple[str, Callable[[T], R], list[T]]

multiprocessing(func: Callable[[T], R], args: list[T], use_starmap: bool = False, chunksize: int = 1, desc: str = '', max_workers: int = 4, delay_first_calls: float = 0, color: str = '\x1b[95m', bar_format: str = '{l_bar}{bar}\x1b[95m| {n_fmt}/{total_fmt} [{rate_fmt}{postfix}, {elapsed}<{remaining}]\x1b[0m', ascii: bool = False) list[R][source]#

Method to execute a function in parallel using multiprocessing, you should use it:

  • For CPU-bound operations where the GIL (Global Interpreter Lock) is a bottleneck.

  • When the task can be divided into smaller, independent sub-tasks that can be executed concurrently.

  • For computationally intensive tasks like scientific simulations, data analysis, or machine learning workloads.

Parameters:
  • func (Callable) – Function to execute

  • args (list) – List of arguments to pass to the function

  • use_starmap (bool) – Whether to use starmap or not (Defaults to False): True means the function will be called like func(*args[i]) instead of func(args[i])

  • chunksize (int) – Number of arguments to process at a time (Defaults to 1 for proper progress bar display)

  • desc (str) – Description displayed in the progress bar (if not provided no progress bar will be displayed)

  • max_workers (int) – Number of workers to use (Defaults to CPU_COUNT)

  • delay_first_calls (float) – Apply i*delay_first_calls seconds delay to the first “max_workers” calls. For instance, the first process will be delayed by 0 seconds, the second by 1 second, etc. (Defaults to 0): This can be useful to avoid functions being called in the same second.

  • color (str) – Color of the progress bar (Defaults to MAGENTA)

  • bar_format (str) – Format of the progress bar (Defaults to BAR_FORMAT)

  • ascii (bool) – Whether to use ASCII or Unicode characters for the progress bar

Returns:

Results of the function execution

Return type:

list[object]

Examples

> multiprocessing(doctest_square, args=[1, 2, 3])
[1, 4, 9]

> multiprocessing(int.__mul__, [(1,2), (3,4), (5,6)], use_starmap=True)
[2, 12, 30]

> # Will process in parallel with progress bar
> multiprocessing(doctest_slow, range(10), desc="Processing")
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

> # Will process in parallel with progress bar and delay the first threads
> multiprocessing(
.     doctest_slow,
.     range(10),
.     desc="Processing with delay",
.     max_workers=2,
.     delay_first_calls=0.6
. )
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
multithreading(func: Callable[[T], R], args: list[T], use_starmap: bool = False, desc: str = '', max_workers: int = 4, delay_first_calls: float = 0, color: str = '\x1b[95m', bar_format: str = '{l_bar}{bar}\x1b[95m| {n_fmt}/{total_fmt} [{rate_fmt}{postfix}, {elapsed}<{remaining}]\x1b[0m', ascii: bool = False) list[R][source]#

Method to execute a function in parallel using multithreading, you should use it:

  • For I/O-bound operations where the GIL is not a bottleneck, such as network requests or disk operations.

  • When the task involves waiting for external resources, such as network responses or user input.

  • For operations that involve a lot of waiting, such as GUI event handling or handling user input.

Parameters:
  • func (Callable) – Function to execute

  • args (list) – List of arguments to pass to the function

  • use_starmap (bool) – Whether to use starmap or not (Defaults to False): True means the function will be called like func(*args[i]) instead of func(args[i])

  • desc (str) – Description displayed in the progress bar (if not provided no progress bar will be displayed)

  • max_workers (int) – Number of workers to use (Defaults to CPU_COUNT)

  • delay_first_calls (float) – Apply i*delay_first_calls seconds delay to the first “max_workers” calls. For instance with value to 1, the first thread will be delayed by 0 seconds, the second by 1 second, etc. (Defaults to 0): This can be useful to avoid functions being called in the same second.

  • color (str) – Color of the progress bar (Defaults to MAGENTA)

  • bar_format (str) – Format of the progress bar (Defaults to BAR_FORMAT)

  • ascii (bool) – Whether to use ASCII or Unicode characters for the progress bar

Returns:

Results of the function execution

Return type:

list[object]

Examples

> multithreading(doctest_square, args=[1, 2, 3])
[1, 4, 9]

> multithreading(int.__mul__, [(1,2), (3,4), (5,6)], use_starmap=True)
[2, 12, 30]

> # Will process in parallel with progress bar
> multithreading(doctest_slow, range(10), desc="Threading")
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

> # Will process in parallel with progress bar and delay the first threads
> multithreading(
.     doctest_slow,
.     range(10),
.     desc="Threading with delay",
.     max_workers=2,
.     delay_first_calls=0.6
. )
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
colored_for_loop(iterable: Iterable[T], desc: str = 'Processing', color: str = '\x1b[95m', bar_format: str = '{l_bar}{bar}\x1b[95m| {n_fmt}/{total_fmt} [{rate_fmt}{postfix}, {elapsed}<{remaining}]\x1b[0m', ascii: bool = False, **kwargs: Any) Iterator[T][source]#

Function to iterate over a list with a colored TQDM progress bar like the other functions in this module.

Parameters:
  • iterable (Iterable) – List to iterate over

  • desc (str) – Description of the function execution displayed in the progress bar

  • color (str) – Color of the progress bar (Defaults to MAGENTA)

  • bar_format (str) – Format of the progress bar (Defaults to BAR_FORMAT)

  • ascii (bool) – Whether to use ASCII or Unicode characters for the progress bar (Defaults to False)

  • verbose (int) – Level of verbosity, decrease by 1 for each depth (Defaults to 1)

  • **kwargs – Additional arguments to pass to the TQDM progress bar

Yields:

T – Each item of the iterable

Examples

>>> for i in colored_for_loop(range(10), desc="Time sleeping loop"):
...     time.sleep(0.01)
>>> # Time sleeping loop: 100%|██████████████████| 10/10 [ 95.72it/s, 00:00<00:00]