j40-cejst-2/data/data-pipeline/data_pipeline/etl/sources/mapping_inequality/etl.py
2022-09-30 13:43:31 -04:00

208 lines
7.7 KiB
Python

import pathlib
import numpy as np
import pandas as pd
from data_pipeline.etl.base import ExtractTransformLoad
from data_pipeline.score import field_names
from data_pipeline.utils import download_file_from_url
from data_pipeline.utils import get_module_logger
logger = get_module_logger(__name__)
class MappingInequalityETL(ExtractTransformLoad):
"""Load Mapping Inequality data.
Information on the source data is available at
https://dsl.richmond.edu/panorama/redlining/.
Information on the mapping of this data to census tracts is available at
https://github.com/americanpanorama/Census_HOLC_Research.
"""
def __init__(self):
self.MAPPING_INEQUALITY_CSV_URL = (
"https://raw.githubusercontent.com/americanpanorama/Census_HOLC_Research/"
"main/2010_Census_Tracts/holc_tract_lookup.csv"
)
self.MAPPING_INEQUALITY_CSV = (
self.get_tmp_path() / "holc_tract_lookup.csv"
)
self.CSV_PATH = self.DATA_PATH / "dataset" / "mapping_inequality"
self.HOLC_MANUAL_MAPPING_CSV_PATH = (
pathlib.Path(__file__).parent
/ "data"
/ "holc_grades_manually_mapped.csv"
)
# Some input field names. From documentation: 'Census Tracts were intersected
# with HOLC Polygons. Census information can be joined via the "geoid" field.
# There are two field "holc_prop" and "tract_prop" which give the proportion
# of the HOLC polygon in the Census Tract and the proportion of Census Tract
# in the HOLC Polygon respectively.'
# https://github.com/americanpanorama/Census_HOLC_Research/blob/main/2010_Census_Tracts/README.md
self.TRACT_INPUT_FIELD: str = "geoid"
self.TRACT_PROPORTION_FIELD: str = "tract_prop"
self.HOLC_GRADE_AND_ID_FIELD: str = "holc_id"
self.CITY_INPUT_FIELD: str = "city"
self.HOLC_GRADE_D_FIELD: str = "HOLC Grade D (hazardous)"
self.HOLC_GRADE_C_FIELD: str = "HOLC Grade C (declining)"
self.HOLC_GRADE_MANUAL_FIELD: str = "HOLC Grade (manually mapped)"
self.HOLC_GRADE_DERIVED_FIELD: str = "HOLC Grade (derived)"
self.COLUMNS_TO_KEEP = [
self.GEOID_TRACT_FIELD_NAME,
field_names.HOLC_GRADE_C_TRACT_PERCENT_FIELD,
field_names.HOLC_GRADE_C_OR_D_TRACT_PERCENT_FIELD,
field_names.HOLC_GRADE_C_OR_D_TRACT_50_PERCENT_FIELD,
field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD,
field_names.HOLC_GRADE_D_TRACT_20_PERCENT_FIELD,
field_names.HOLC_GRADE_D_TRACT_50_PERCENT_FIELD,
field_names.HOLC_GRADE_D_TRACT_75_PERCENT_FIELD,
field_names.REDLINED_SHARE,
]
self.df: pd.DataFrame
def extract(self) -> None:
logger.info("Downloading Mapping Inequality Data")
download_file_from_url(
file_url=self.MAPPING_INEQUALITY_CSV_URL,
download_file_name=self.MAPPING_INEQUALITY_CSV,
)
def transform(self) -> None:
logger.info("Transforming Mapping Inequality Data")
df: pd.DataFrame = pd.read_csv(
self.MAPPING_INEQUALITY_CSV,
dtype={self.TRACT_INPUT_FIELD: "string"},
low_memory=False,
)
# rename Tract ID
df.rename(
columns={
self.TRACT_INPUT_FIELD: self.GEOID_TRACT_FIELD_NAME,
},
inplace=True,
)
# Keep the first character, which is the HOLC grade (A, B, C, D).
# TODO: investigate why this dataframe triggers these pylint errors.
# pylint: disable=unsupported-assignment-operation, unsubscriptable-object
df[self.HOLC_GRADE_DERIVED_FIELD] = df[
self.HOLC_GRADE_AND_ID_FIELD
].str[0:1]
# Remove nonsense when the field has no grade or invalid grades.
valid_grades = ["A", "B", "C", "D"]
df.loc[
# pylint: disable=unsubscriptable-object
~df[self.HOLC_GRADE_DERIVED_FIELD].isin(valid_grades),
self.HOLC_GRADE_DERIVED_FIELD,
] = None
# Some data needs to be manually mapped to its grade.
# TODO: Investigate more data that may need to be manually mapped.
holc_manually_mapped_df = pd.read_csv(
filepath_or_buffer=self.HOLC_MANUAL_MAPPING_CSV_PATH,
low_memory=False,
)
# Join on the existing data
merged_df = df.merge(
right=holc_manually_mapped_df,
on=[self.HOLC_GRADE_AND_ID_FIELD, self.CITY_INPUT_FIELD],
how="left",
)
# Create a single field that combines the 'derived' grade C and D fields with the
# manually mapped grade C and D field into a single grade C and D field.
## Note: there are no manually derived C tracts at the moment
for grade, field_name in [
("C", self.HOLC_GRADE_C_FIELD),
("D", self.HOLC_GRADE_D_FIELD),
]:
merged_df[field_name] = np.where(
(merged_df[self.HOLC_GRADE_DERIVED_FIELD] == grade)
| (merged_df[self.HOLC_GRADE_MANUAL_FIELD] == grade),
True,
None,
)
redlined_dataframes_list = [
merged_df[merged_df[field].fillna(False)]
.groupby(self.GEOID_TRACT_FIELD_NAME)[self.TRACT_PROPORTION_FIELD]
.sum()
.rename(new_name)
for field, new_name in [
(
self.HOLC_GRADE_D_FIELD,
field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD,
),
(
self.HOLC_GRADE_C_FIELD,
field_names.HOLC_GRADE_C_TRACT_PERCENT_FIELD,
),
]
]
# Group by tract ID to get tract proportions of just C or just D
# This produces a single row per tract
grouped_df = (
pd.concat(
redlined_dataframes_list,
axis=1,
)
.fillna(0)
.reset_index()
)
grouped_df[
field_names.HOLC_GRADE_C_OR_D_TRACT_PERCENT_FIELD
] = grouped_df[
[
field_names.HOLC_GRADE_C_TRACT_PERCENT_FIELD,
field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD,
]
].sum(
axis=1
)
# Calculate some specific threshold cutoffs, for convenience.
grouped_df[field_names.HOLC_GRADE_D_TRACT_20_PERCENT_FIELD] = (
grouped_df[field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD] > 0.2
)
grouped_df[field_names.HOLC_GRADE_D_TRACT_50_PERCENT_FIELD] = (
grouped_df[field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD] > 0.5
)
grouped_df[field_names.HOLC_GRADE_D_TRACT_75_PERCENT_FIELD] = (
grouped_df[field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD] > 0.75
)
grouped_df[field_names.HOLC_GRADE_C_OR_D_TRACT_50_PERCENT_FIELD] = (
grouped_df[field_names.HOLC_GRADE_C_OR_D_TRACT_PERCENT_FIELD] > 0.5
)
# Create the indicator we will use
grouped_df[field_names.REDLINED_SHARE] = (
grouped_df[field_names.HOLC_GRADE_C_OR_D_TRACT_PERCENT_FIELD] > 0.5
) & (grouped_df[field_names.HOLC_GRADE_D_TRACT_PERCENT_FIELD] > 0)
# Sort for convenience.
grouped_df.sort_values(by=self.GEOID_TRACT_FIELD_NAME, inplace=True)
# Save to self.
self.df = grouped_df
def load(self) -> None:
logger.info("Saving Mapping Inequality CSV")
# write nationwide csv
self.CSV_PATH.mkdir(parents=True, exist_ok=True)
self.df[self.COLUMNS_TO_KEEP].to_csv(
self.CSV_PATH / "usa.csv", index=False
)