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Changelog

0.3.1 (2026)

Changed

  • Shapefile downloads now use pygris — The internal _fetch_tiger_shapes() function now delegates to pygris instead of manually constructing Census Bureau URLs. The public API (geometry=True, attach_geometry()) is unchanged.

Added

  • Automatic shapefile caching — Downloaded shapefiles are cached locally via pygris (~/Library/Caches/pygris/ on macOS, ~/.cache/pygris/ on Linux). Repeated geometry=True calls no longer re-download files.
  • cache parameter on attach_geometry() — Pass cache=False to force a fresh download.
  • Clear error for missing state — Sub-state geographies (tract, block group, place, puma) now raise a ValueError with a helpful message when state is omitted.

Fixed

  • ZCTA and PUMA geometry for pre-2020 years — Previously broken due to hardcoded 2020 vintage suffixes. pygris handles vintage selection correctly.
  • Congressional district year mapping — Previously used a hardcoded formula. pygris handles this internally.

Improved

  • Broader year range — Geometry support extended from ~2014+ to ~1990+ for most geography levels.
  • Faster county downloads — County-level queries now pass state through to pygris when provided, downloading a smaller state-specific file.

Dependencies

  • Added pygris>=0.1.7,<1 to the spatial optional dependency group.

0.3 (2026)

Version bump. No user-facing changes from 0.2.

0.2 (2026)

Major release with complete Census API feature parity with R’s tidycensus.

Added

  • get_acs() — Retrieve American Community Survey data via the Census API

    • Tidy and wide output formats
    • MOE confidence level scaling (90%, 95%, 99%)
    • Summary variable support for proportion calculations
    • Geometry attachment (returns GeoDataFrame)
    • keep_geo_vars option to preserve raw FIPS columns
    • Built-in caching with configurable TTL

  • get_decennial() — Retrieve Decennial Census data (2000, 2010, 2020)

    • Population group support for DHC-A disaggregated data
    • Tidy and wide output formats
    • Geometry support

  • get_pums() — Load PUMS microdata from the Census API

    • Server-side variable filtering
    • Person and housing replicate weights (80 columns each)
    • Variable recoding with human-readable labels
    • Multi-state queries
    • PUMA-level filtering

  • get_estimates() — Population Estimates Program data

    • Products: population, components, housing, characteristics
    • Breakdown dimensions (age, sex, race, Hispanic origin)
    • Time series support
    • Vintage-based queries

  • get_flows() — ACS Migration Flows data

    • County and MSA-level flows
    • Breakdown labels from migration recodes
    • MOE confidence scaling
    • Geometry support for origin geography

  • load_variables() — Browse and search Census variable metadata

    • In-memory and persistent disk caching
    • Search across datasets: acs5, acs1, pl, acs5/subject, acs5/profile

  • MOE functions — Margin of error calculations from ACS General Handbook

    • moe_sum() — Combined MOE for derived sums
    • moe_ratio() — MOE for derived ratios
    • moe_prop() — MOE for derived proportions
    • moe_product() — MOE for derived products
    • significance() — Statistical significance testing

  • Spatial support — Cartographic boundary integration

    • attach_geometry() — Merge shapefiles with Census data
    • as_dot_density() — Dot-density point conversion
    • interpolate_pw() — Population-weighted areal interpolation
    • Multiple resolution levels: 500k, 5m, 20m

  • Survey design — Replicate weight standard errors

    • SurveyDesign class with SDR method
    • to_survey() helper for PUMS DataFrames
    • Weighted estimates and means

  • get_survey_metadata() — Census API dataset discovery

  • Census helpers

    • summary_files() — List available decennial summary files
    • get_pop_groups() — Population groups for DHC-A

  • Reference datasets (pypums.datasets)

    • fips_codes — State/county FIPS lookup table
    • lookup_fips() / lookup_name() — FIPS code resolution
    • mig_recodes — Migration flow labels
    • pums_variables() — PUMS variable dictionary
    • acs5_geography() — Available ACS5 geographies

  • Geography system — Hierarchical query building for 20+ geography levels

  • Caching system — Parquet-based file caching with SHA256 keys and TTL

  • CLI commands — pypums acs, pypums decennial, pypums variables, pypums estimates, pypums config

Deprecated

  • ACS class — Use get_acs() and get_pums() instead

0.0.7 (2020-06-23)

  • Fixes bug where _check_data_folder() would ignore the path parameter
  • Uses path.mkdir(..., exists_ok=True)
  • Adds 2018 to possible survey years
  • First contributor! @yonran

0.0.6 (2020-05-23)

  • Bug fixes (some URLs at the Census website didn’t have content-size)

0.0.5 (2019-05-11)

  • Add .as_dataframe() to ACS class

0.0.4 (2019-05-10)

  • Add .download_data() to ACS class

0.0.3 (2019-05-09)

  • Accidentally released

0.0.2 (2019-05-09)

  • Add ACS() class for Python interface

0.0.1 (2019-04-29)

  • First release on PyPI