Implementation:Evidentlyai Evidently Legacy Contains Link Feature

Knowledge Sources	Evidentlyai_Evidently
Domains	ML Monitoring, NLP, Text Quality
Last Updated	2026-02-14 12:00 GMT

Overview

Detects whether a text column contains URLs/links by parsing each word with Python's urlparse and checking for valid scheme and netloc components.

Description

The ContainsLink class extends ApplyColumnGeneratedFeature to produce a categorical feature indicating whether each text value contains at least one valid URL. The detection logic works by splitting the text into whitespace-delimited words and passing each word through urllib.parse.urlparse. A word is considered a valid link if both the scheme (e.g., "http", "https") and netloc (e.g., "example.com") components are present.

The feature type is Categorical (returning True/False), and the default display name follows the template "{column_name} contains link". Null or NaN values return 0 (falsy).

This is a lightweight, dependency-free link detection approach that does not require external NLP libraries -- it relies solely on Python's standard library urllib.parse module.

Usage

Use this feature when monitoring text outputs for the presence of URLs, such as checking whether LLM-generated responses contain links (which may be undesirable in certain contexts) or ensuring that text fields expected to contain references actually include URLs.

Code Reference

Source Location

• Repository: Evidentlyai_Evidently
• File: src/evidently/legacy/features/contains_link_feature.py

Signature

class ContainsLink(ApplyColumnGeneratedFeature):
    class Config:
        type_alias = "evidently:feature:ContainsLink"

    __feature_type__: ClassVar = ColumnType.Categorical
    display_name_template: ClassVar = "{column_name} contains link"

    def __init__(self, column_name: str, display_name: Optional[str] = None): ...
    def apply(self, value: Any): ...

Import

from evidently.legacy.features.contains_link_feature import ContainsLink

I/O Contract

Inputs

Name	Type	Required	Description
column_name	str	Yes	The name of the text column to check for links.
display_name	Optional[str]	No	Custom display name for the feature. Defaults to "{column_name} contains link".

Outputs

Name	Type	Description
return	pd.DataFrame	A single-column DataFrame with boolean values (True if a link is found, False/0 otherwise).

Usage Examples

from evidently.legacy.features.contains_link_feature import ContainsLink

# Check if the "response" column contains links
link_feature = ContainsLink(column_name="response")

# With a custom display name
link_feature = ContainsLink(
    column_name="assistant_reply",
    display_name="Reply Contains URL",
)

# The apply method can be used directly for testing
link_feature.apply("Visit https://example.com for details")  # Returns True
link_feature.apply("No links here")                           # Returns False
link_feature.apply(None)                                      # Returns 0

Related Pages

• Environment:Evidentlyai_Evidently_Python_Core_Environment
• Evidentlyai_Evidently_Legacy_Generated_Features - Base class ApplyColumnGeneratedFeature that ContainsLink extends.
• Evidentlyai_Evidently_Legacy_OOV_Words_Feature - Another text quality feature using the same ApplyColumnGeneratedFeature pattern.