CQE 1.0.2

quantity extractor

CQE

Evaultion and data in CQE_Evaluation.

A Framework for Comprehensive Quantity Extraction. This repository contains code for the paper:

CQE: A Framework for Comprehensive Quantity Extraction

Satya Almasian*, Vivian Kazakova*, Philipp Göldner, Michael Gertz
Institute of Computer Science, Heidelberg University
(* indicates equal contribution)

If you found this useful, consider citing us:

@misc{almasian2023cqe,
      title={CQE: A Comprehensive Quantity Extractor}, 
      author={Satya Almasian and Vivian Kazakova and Philip Göldner and Michael Gertz},
      year={2023},
      eprint={2305.08853},
      archivePrefix={arXiv},
      primaryClass={cs.CL}
}

Prerequisites

you can also install the package using on the root directory of the package.

pip install .

or simply via pip:

pip install CQE

Usage

Create a NumParser and parse some text or sentence.

from CQE.NumParser import NumParser

parser = NumParser()
text = "The sp 500 was down 2.1% and nasdaq fell 2.5%."
result = parser.parse(text)
print(result)

>>> [(=,2.1,[%],percentage,[sp, 500]), (=,2.5,[%],percentage,[nasdaq])]

Use the overload option for additional functionality. The NumParser will compute the span indices of the Quantity, the normalized input sentence, the long and the simplified scientific notation of the Value, whether the unit is scientific or noun based and the unit surface forms.

parser = NumParser(overload=True)
text = "The sp 500 was down 2.1% and nasdaq fell 2.5%."
result = parser.parse(text)

for res in result:
    print(f"""
	Quantity: {res}
	=====
	indices                         =   {res.get_char_indices()}
	normalized text                 =   {res.get_normalized_text()}
	pre processed text              =   {res.get_preprocessed_text()}
	scientific notation             =   {res.value.scientific_notation}
	simplified scientific notation  =   {res.value.simplified_scientific_notation}
	scientific unit                 =   {res.unit.scientific}
	unit surfaces forms             =   {res.unit.unit_surfaces_forms}""")

>>> Quantity: (down,2.1,[%],percentage,{0: [sp, 500]})
=====
indices                         =   [5, 6]
normalized text                 =   The sp 500 was down 2.1 percentage and nasdaq fell 2.5 percentage .
pre processed text              =   The sp 500 was down 2.1% and nasdaq fell 2.5% .
scientific notation             =   2.100000e+00
simplified scientific notation  =   2.1e+00
scientific unit                 =   True
unit surfaces forms             =   ['percentage', 'percent', 'pc', '%', 'pct', 'pct.']


Quantity: (down,2.5,[%],percentage,{0: [nasdaq]})
=====
indices                         =   [10, 11]
normalized text                 =   The sp 500 was down 2.1 percentage and nasdaq fell 2.5 percentage .
pre processed text              =   The sp 500 was down 2.1% and nasdaq fell 2.5% .
scientific notation             =   2.500000e+00
simplified scientific notation  =   2.5e+00
scientific unit                 =   True
unit surfaces forms             =   ['percentage', 'percent', 'pc', '%', 'pct', 'pct.']

See the example in CQE/example.py as well. Run

python3 CQE/example.py

Evaluation and Data

For replicating the results on the paper and comparing against other system, make sure CQE is installed and use the CQE_Evaluation repo. The evaluation script and data used for evaluation and training unit disambiguators are in this repository.

File and folder structure

Main files for CQE are under CQE package, where unit_classifer contains code for unit disambiguation based on BERT classifier trained using spacy-transformers. units.json file is used for normalization of units and unit_models.zip contains the trained models for the disambiguation which will be unziped on the first run of NumParserclass.

File	Description
CQE/NumberNormalizer.py	Bound, Number and Unit Normalization script
CQE/NumberParser.py	Quantity Extraction script
CQE/rules.py	Rules for DependencyMatcher
CQE/unit.json	531 units used for the Unit Normalization
CQE/classes.py	Definition of the Bound, Range, Number, Unit, Noun and Quanitity classes
CQE/number_lookup.py	Number-word to number mappings
CQE/example.py	Usage example
CQE/unit_classifer/unit_disambiguator.py	Class for unit disambiguator based on the bert based classifiers.
CQE/unit_classifer/train_classifier_bert.py	Script for generating spacy based training data and training commands to create classifiers for disambiguation.
CQE/unit_classifer/sample_usage.py	Usage example for disambiguation class.

Units

The units used for normalization of the unit of an extracted quantity are stored in the unit.json . Each of the 531 units has surfaces, symbols, prefixes, entity, URI, dimensions and currency_code. For composing the file, the list of units from quantulum3, the list of units from Wikipedia, the surfaces from Microsoft.Recognizers.Text ,the UCUM units and surfaces and wikipedia page of [units] (https://en.wikipedia.org/wiki/Template:Convert/list_of_units) were used.

Example:

"light-year":  {
	"surfaces":  [
		"light-year",
		"light year",
		"light years"
	],
	"entity":  "length",
	"URI":  "Light-year",
	"dimensions":  [],
	"symbols":  [
		"ly",
		"[ly]"
	]
}

Rules

There are more than 50 rules for DependencyMatcher defined in the rules.py. We use the spaCy-model en core web sm to create a Doc object with linguistic annotations. The key point is that the rules are not simple pattern matching based on the single words in the sentence, but on those annotations and exploit the structure of the sentence.

Existing rules can be changed and new ones can be added by editing the file. Pay attention to the DependencyMatcher syntax.

Example:

"num_symbol"  :  [
	{
		"RIGHT_ID":  "number",
		"RIGHT_ATTRS":  {"POS":  "NUM"}
	},
	{
		"LEFT_ID":  "number",
		"REL_OP":  ">",
		"RIGHT_ID":  "symbol",
		"RIGHT_ATTRS":  {"DEP":  {"IN":  ["quantmod",  "nmod"]},  "POS":  "SYM"}
	},
]

Input: "The September crude contract was up 19 cents at US $58.24 per barrel and the September natural gas contract was up 10.4 cents to US $2.24 per mmBTU."

Matches:
NUM_SYMBOL [58.24, US$]
NUM_SYMBOL [2.24, US$]
NOUN_NUM [cents, 19]
NOUN_NUM [cents, 10.4]
NUM_RIGHT_NOUN [58.24, barrel]
NUM_RIGHT_NOUN [2.24, mmBTU]
NOUN_NOUN [contract, gas, natural]
UNIT_FRAC [58.24, per, barrel]
UNIT_FRAC [58.24, per, gas]
UNIT_FRAC [58.24, per, contract]
UNIT_FRAC [58.24, per, cents]
UNIT_FRAC [58.24, per, mmBTU]
UNIT_FRAC [2.24, per, mmBTU]
UNIT_FRAC_2 [58.24, per, gas, natural]
LONELY_NUM [19]
LONELY_NUM [58.24]
LONELY_NUM [10.4]
LONELY_NUM [2.24]

Candidates: [[US$, 58.24, per, barrel, 10], [US$, 2.24, per, mmBTU, 25], [19, cents, 6], [10.4, cents, 21]]
Quadruples: [([], [58.24], [US$, per, barrel], 10), ([], [2.24], [US$, per, mmBTU], 25), ([], [19], [cents], 6), ([], [10.4], [cents], 21)]

Output: [(=,58.24,[US$, per, barrel],united states dollar / barrel,[September, crude, contract]), (=,2.24,[US$, per, mmBTU],united states dollar / mmBTU,[September, natural, gas, contract]), (=,19.0,[cents],cent,[September, crude, contract]), (=,10.4,[cents],cent,[September, natural, gas, contract])]

Note that the numbers 6, 10, 21 and 25 indicate the position of the quantity in the text.