Description #

Special character ratio calculator - Text feature extraction based on the proportion of special characters

Key features #

• Special character ratio calculation: Accurately calculates the proportion of special characters in text
• Multi-granularity support: Allows selection of different types of special characters for calculation
• Flexible configuration: Supports calculating the ratio of all special characters or specific types of characters

Application scenarios #

• Text quality assessment
• Data cleaning and preprocessing
• Text classification feature extraction
• Content security detection
• Multilingual text analysis

Technical features #

• Supports multiple character types:
  • all: All special characters (default)
  • whitespace: Whitespace characters
  • punctuation: Punctuation marks
  • digits: Digit characters
  • emoji: Emoji symbols
• Supports multilingual Unicode character recognition

Operator parameters #

Input #

Output #

Ratio result column, elements are floating-point numbers representing the proportion of special characters

Parameters #

If a parameter does not have a default value, it is required

Examples #

The following code demonstrates how to use daft to run the operator and calculate the proportion of special characters in text.

from __future__ import annotations

import os

import daft
from daft import col
from daft.las.functions.text.special_characters_ratio_calculator import SpecialCharactersRatioCalculator
from daft.las.functions.udf import las_udf

if __name__ == "__main__":

    if os.getenv("DAFT_RUNNER", "native") == "ray":
        import logging

        import ray

        def configure_logging():
            logging.basicConfig(
                level=logging.INFO,
                format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
                datefmt="%Y-%m-%d %H:%M:%S.%s".format(),
            )
            logging.getLogger("tracing.span").setLevel(logging.WARNING)
            logging.getLogger("daft_io.stats").setLevel(logging.WARNING)
            logging.getLogger("DaftStatisticsManager").setLevel(logging.WARNING)
            logging.getLogger("DaftFlotillaScheduler").setLevel(logging.WARNING)
            logging.getLogger("DaftFlotillaDispatcher").setLevel(logging.WARNING)

        ray.init(dashboard_host="0.0.0.0", runtime_env={"worker_process_setup_hook": configure_logging})
        daft.set_runner_ray()
    daft.set_execution_config(actor_udf_ready_timeout=600)
    daft.set_execution_config(min_cpu_per_task=0)

    samples = {
        "text": [
            "Hello world!",
            "1234567890",
            "     ",
            "这是中文文本",
            "你好 Hello 😊 123 !!!",
        ]
    }

    ds = daft.from_pydict(samples)
    ds = ds.with_column(
        "special_ratio",
        las_udf(
            SpecialCharactersRatioCalculator,
            construct_args={"character_type": "all"},
        )(col("text")),
    )

    ds.show()
    # ╭───────────────────────┬─────────────────────╮
    # │ text                  ┆ special_ratio       │
    # │ ---                   ┆ ---                 │
    # │ String                ┆ Float64             │
    # ╞═══════════════════════╪═════════════════════╡
    # │ Hello world! ┆ 0.16666666666666666 │
    # ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
    # │ 1234567890            ┆ 1                   │
    # ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
    # │                       ┆ None                │
    # ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
    # │ 这是中文文本          ┆ 0                   │
    # ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
    # │ 你好 Hello 😊 123 !!! ┆ 0.6111111111111112  │
    # ╰───────────────────────┴─────────────────────╯