Dates

The eds.dates pipeline's role is to detect and normalise dates within a medical document. We use simple regular expressions to extract date mentions, and apply the dateparser library for the normalisation.

Warning

The dates pipeline is still in active development and has not been rigorously validated. If you come across a date expression that goes undetected, please file an issue !

Scope

The eds.dates pipeline finds absolute (eg 23/08/2021) and relative (eg hier, la semaine dernière) dates alike.

If the date of edition (via the doc._.note_datetime extension) is available, relative (and "year-less") dates will be normalised using the latter as base. On the other hand, if the base is unknown, the normalisation will follow the pattern : TD±<number-of-days>, positive values meaning that the relative date mentions the future (dans trois jours).

Since the extension doc._.note_datetime cannot be set before applying the dates pipeline, we defer the normalisation step until the span._.dates attribute is accessed.

See the tutorial for a presentation of a full pipeline featuring the eds.dates component.

Usage

import spacy

from datetime import datetime

nlp = spacy.blank("fr")
nlp.add_pipe("eds.dates")

text = (
    "Le patient est admis le 23 août 2021 pour une douleur à l'estomac. "
    "Il lui était arrivé la même chose il y a un an."
)

doc = nlp(text)

dates = doc.spans["dates"]
dates
# Out: [23 août 2021, il y a un an]

dates[0]._.date
# Out: "2021-08-23"

dates[1]._.date
# Out: "TD-365"

doc._.note_datetime = datetime(2021, 8, 27)

dates[1]._.date
# Out: "2020-08-27"

Declared extensions

The eds.dates pipeline declares two spaCy extensions on the Span object :

1. The date_parsed attribute is a Python datetime object, used internally by the pipeline.
2. The date attribute is a property that displays a normalised human-readable string for the date.

Configuration

The pipeline can be configured using the following parameters :

Parameter	Explanation	Default
no_year	Date patterns without year, eg le 5 août	None (use pre-defined patterns)
year_only	Date patterns with only the year, eg en 2018	None (use pre-defined patterns)
no_day	Date patterns without day, eg en mars 2018	None (use pre-defined patterns)
absolute	Absolute date patterns, eg le 5 août 2020	None (use pre-defined patterns)
relative	Relative date patterns, eg hier)	None (use pre-defined patterns)
full	Full date patterns, eg 2020-10-23	None (use pre-defined patterns)
current	"Current" date patterns, eg ce jour	None (use pre-defined patterns)
false_positive	Some false positive patterns to exclude	None (use pre-defined patterns)
on_ents_only	Whether to look for dates around entities only	False
attr	spaCy attribute to match on, eg NORM or TEXT	"NORM"

Authors and citation

The eds.dates pipeline was developed by AP-HP's Data Science team.