app.py

'''Streamlit app for Student Name Detection models.'''
import json
import os
import warnings
from json import JSONEncoder

import pandas as pd
import streamlit as st
from annotated_text import annotated_text

from piilo.engines.analyzer import CustomAnalyzer
from piilo.engines.anonymizer import SurrogateAnonymizer

os.environ['TOKENIZERS_PARALLELISM'] = 'false'
warnings.filterwarnings('ignore')

# Helper methods
@st.cache(allow_output_mutation=True)
def analyzer_engine():
    '''Return AnalyzerEngine and cache with Streamlit.'''

    configuration = {
        'nlp_engine_name': 'spacy',
        'models': [
            {'lang_code': 'en', 'model_name': 'en_student_name_detector'}],
    }

    return CustomAnalyzer(configuration=configuration)

@st.cache(allow_output_mutation=True)
def anonymizer_engine():
    '''Return generate surrogate anonymizer.'''
    return SurrogateAnonymizer()

def annotate(text, st_analyze_results, st_entities):
    tokens = []
    # sort by start index
    results = sorted(st_analyze_results, key=lambda x: x.start)
    for i, res in enumerate(results):
        if i == 0:
            tokens.append(text[:res.start])

        # append entity text and entity type
        tokens.append((text[res.start: res.end], res.entity_type))

        # if another entity coming i.e. we're not at the last results element, add text up to next entity
        if i != len(results) - 1:
            tokens.append(text[res.end:results[i+1].start])
        # if no more entities coming, add all remaining text
        else:
            tokens.append(text[res.end:])
    return tokens


st.set_page_config(page_title='Student Name Detector (English)', layout='wide')

# Side bar
st.sidebar.image('logo.png')

st.sidebar.markdown(
    '''Detect and anonymize PII in text using an [NLP model](https://huggingface.co/langdonholmes/en_student_name_detector) [trained](https://github.com/aialoe/deidentification-pipeline) on student-generated text collected from a massive online open-enrollment course.
'''
)

st_entities = st.sidebar.multiselect(
    label='Which entities to look for?',
    options=analyzer_engine().get_supported_entities(),
    default=list(analyzer_engine().get_supported_entities()),
)

st_threshold = st.sidebar.slider(
    label='Acceptance threshold', min_value=0.0, max_value=1.0, value=0.35
)

st_return_decision_process = st.sidebar.checkbox(
    'Add analysis explanations in json')

st.sidebar.info(
    'This is part of a project to develop new anonymization systems that are appropriate for student-generated text.'
)

# Main panel
analyzer_load_state = st.info(
    'Starting Presidio analyzer and loading Longformer-based model...')
engine = analyzer_engine()
analyzer_load_state.empty()


st_text = st.text_area(
    label='Type in some text',
    value='Learning Reflection\n\nWritten by John Williams and Samantha Morales\n\nIn this course I learned many things. As Liedtke (2004) said, \"Students grow when they learn\" (Erickson et al. 1998).\n\nBy John H. Williams -- (714) 328-9989 -- johnwilliams@yahoo.com',
    height=200,
)

button = st.button('Detect PII')

if 'first_load' not in st.session_state:
    st.session_state['first_load'] = True

# After
st.subheader('Analyzed')
with st.spinner('Analyzing...'):
    if button or st.session_state.first_load:
        st_analyze_results = analyzer_engine().analyze(
            text=st_text,
            entities=st_entities,
            language='en',
            score_threshold=st_threshold,
            return_decision_process=st_return_decision_process,
        )
        annotated_tokens = annotate(st_text, st_analyze_results, st_entities)
        # annotated_tokens
        annotated_text(*annotated_tokens)

# vertical space
st.text('')

st.subheader('Anonymized')
with st.spinner('Anonymizing...'):
    if button or st.session_state.first_load:
        st_anonymize_results = anonymizer_engine().anonymize(
                                         st_text,
                                         st_analyze_results)
        st_anonymize_results
        
# table result
st.subheader('Detailed Findings')
if st_analyze_results:
    res_dicts = [r.to_dict() for r in st_analyze_results]
    for d in res_dicts:
        d['Value'] = st_text[d['start']:d['end']]
    df = pd.DataFrame.from_records(res_dicts)
    df = df[['entity_type', 'Value', 'score', 'start', 'end']].rename(
        {
            'entity_type': 'Entity type',
            'start': 'Start',
            'end': 'End',
            'score': 'Confidence',
        },
        axis=1,
    )

    st.dataframe(df, width=1000)
else:
    st.text('No findings')

st.session_state['first_load'] = True

# json result
class ToDictListEncoder(JSONEncoder):
    '''Encode dict to json.'''

    def default(self, o):
        '''Encode to JSON using to_dict.'''
        if o:
            return o.to_dict()
        return []

if st_return_decision_process:
    st.json(json.dumps(st_analyze_results, cls=ToDictListEncoder))