Add pagination offset support for API queries

Implements offset parameter to enable pagination within the 10k API limit. Users can now fetch results in chunks (e.g., offset=200, limit=200 for results 200-399). Includes validation to ensure offset + limit doesn't exceed API maximum. Also fixes multi-page result sorting to preserve correct order across page boundaries.

Fixes #139

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Zachary Hampton
2025-11-05 10:57:01 -08:00
parent 1608020b69
commit 21b6ba44f4
7 changed files with 195 additions and 33 deletions

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@@ -278,7 +278,9 @@ Optional
├── exclude_pending (True/False): If set, excludes 'pending' properties from the 'for_sale' results unless listing_type is 'pending'
── limit (integer): Limit the number of properties to fetch. Max & default is 10000.
── limit (integer): Limit the number of properties to fetch. Max & default is 10000.
└── offset (integer): Starting position for pagination within the 10k limit. Use with limit to fetch results in chunks.
```
### Property Schema

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@@ -1,7 +1,7 @@
import warnings
import pandas as pd
from .core.scrapers import ScraperInput
from .utils import process_result, ordered_properties, validate_input, validate_dates, validate_limit, validate_datetime, validate_filters, validate_sort
from .utils import process_result, ordered_properties, validate_input, validate_dates, validate_limit, validate_offset, validate_datetime, validate_filters, validate_sort
from .core.scrapers.realtor import RealtorScraper
from .core.scrapers.models import ListingType, SearchPropertyType, ReturnType, Property
from typing import Union, Optional, List
@@ -21,6 +21,7 @@ def scrape_property(
extra_property_data: bool = True,
exclude_pending: bool = False,
limit: int = 10000,
offset: int = 0,
# New date/time filtering parameters
past_hours: int = None,
datetime_from: str = None,
@@ -61,6 +62,7 @@ def scrape_property(
:param extra_property_data: Increases requests by O(n). If set, this fetches additional property data (e.g. agent, broker, property evaluations etc.)
:param exclude_pending: If true, this excludes pending or contingent properties from the results, unless listing type is pending.
:param limit: Limit the number of results returned. Maximum is 10,000.
:param offset: Starting position for pagination within the 10k limit (offset + limit cannot exceed 10,000). Use with limit to fetch results in chunks (e.g., offset=200, limit=200 fetches results 200-399). Should be a multiple of 200 (page size) for optimal performance. Default is 0. Note: Cannot be used to bypass the 10k API limit - use date ranges (date_from/date_to) to narrow searches and fetch more data.
New parameters:
:param past_hours: Get properties in the last _ hours (requires client-side filtering)
@@ -77,6 +79,7 @@ def scrape_property(
validate_input(listing_type)
validate_dates(date_from, date_to)
validate_limit(limit)
validate_offset(offset, limit)
validate_datetime(datetime_from)
validate_datetime(datetime_to)
validate_filters(
@@ -100,6 +103,7 @@ def scrape_property(
extra_property_data=extra_property_data,
exclude_pending=exclude_pending,
limit=limit,
offset=offset,
# New date/time filtering
past_hours=past_hours,
datetime_from=datetime_from,

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@@ -25,6 +25,7 @@ class ScraperInput(BaseModel):
extra_property_data: bool | None = True
exclude_pending: bool | None = False
limit: int = 10000
offset: int = 0
return_type: ReturnType = ReturnType.pandas
# New date/time filtering parameters
@@ -106,6 +107,7 @@ class Scraper:
self.extra_property_data = scraper_input.extra_property_data
self.exclude_pending = scraper_input.exclude_pending
self.limit = scraper_input.limit
self.offset = scraper_input.offset
self.return_type = scraper_input.return_type
# New date/time filtering

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@@ -405,13 +405,23 @@ class RealtorScraper(Scraper):
if self.return_type != ReturnType.raw:
with ThreadPoolExecutor(max_workers=self.NUM_PROPERTY_WORKERS) as executor:
futures = [executor.submit(process_property, result, self.mls_only, self.extra_property_data,
self.exclude_pending, self.listing_type, get_key, process_extra_property_details) for result in properties_list]
# Store futures with their indices to maintain sort order
futures_with_indices = [
(i, executor.submit(process_property, result, self.mls_only, self.extra_property_data,
self.exclude_pending, self.listing_type, get_key, process_extra_property_details))
for i, result in enumerate(properties_list)
]
for future in as_completed(futures):
# Collect results and sort by index to preserve API sort order
results = []
for idx, future in futures_with_indices:
result = future.result()
if result:
properties.append(result)
results.append((idx, result))
# Sort by index and extract properties in correct order
results.sort(key=lambda x: x[0])
properties = [result for idx, result in results]
else:
properties = properties_list
@@ -428,7 +438,7 @@ class RealtorScraper(Scraper):
location_type = location_info["area_type"]
search_variables = {
"offset": 0,
"offset": self.offset,
}
search_type = (
@@ -473,21 +483,30 @@ class RealtorScraper(Scraper):
homes = result["properties"]
with ThreadPoolExecutor() as executor:
futures = [
executor.submit(
# Store futures with their offsets to maintain proper sort order
# Start from offset + page_size and go up to offset + limit
futures_with_offsets = [
(i, executor.submit(
self.general_search,
variables=search_variables | {"offset": i},
search_type=search_type,
)
))
for i in range(
self.DEFAULT_PAGE_SIZE,
min(total, self.limit),
self.offset + self.DEFAULT_PAGE_SIZE,
min(total, self.offset + self.limit),
self.DEFAULT_PAGE_SIZE,
)
]
for future in as_completed(futures):
homes.extend(future.result()["properties"])
# Collect results and sort by offset to preserve API sort order across pages
results = []
for offset, future in futures_with_offsets:
results.append((offset, future.result()["properties"]))
# Sort by offset and concatenate in correct order
results.sort(key=lambda x: x[0])
for offset, properties in results:
homes.extend(properties)
# Apply client-side hour-based filtering if needed
# (API only supports day-level filtering, so we post-filter for hour precision)
@@ -498,6 +517,11 @@ class RealtorScraper(Scraper):
elif self.listing_type == ListingType.PENDING and (self.last_x_days or self.date_from):
homes = self._apply_pending_date_filter(homes)
# Apply client-side sort to ensure results are properly ordered
# This is necessary after filtering and to guarantee sort order across page boundaries
if self.sort_by:
homes = self._apply_sort(homes)
return homes
def _apply_hour_based_date_filter(self, homes):
@@ -722,6 +746,60 @@ class RealtorScraper(Scraper):
return date_range['from_date'] <= date_obj <= date_range['to_date']
return False
def _apply_sort(self, homes):
"""Apply client-side sorting to ensure results are properly ordered.
This is necessary because:
1. Multi-page results need to be re-sorted after concatenation
2. Filtering operations may disrupt the original sort order
Args:
homes: List of properties (either dicts or Property objects)
Returns:
Sorted list of properties
"""
if not homes or not self.sort_by:
return homes
def get_sort_key(home):
"""Extract the sort field value from a home (handles both dict and Property object)."""
if isinstance(home, dict):
value = home.get(self.sort_by)
else:
# Property object
value = getattr(home, self.sort_by, None)
# Handle None values - push them to the end
if value is None:
# Use a sentinel value that sorts to the end
return (1, 0) if self.sort_direction == "desc" else (1, float('inf'))
# For datetime fields, convert string to datetime for proper sorting
if self.sort_by in ['list_date', 'sold_date', 'pending_date']:
if isinstance(value, str):
try:
from datetime import datetime
# Handle timezone indicators
date_value = value
if date_value.endswith('Z'):
date_value = date_value[:-1] + '+00:00'
parsed_date = datetime.fromisoformat(date_value)
return (0, parsed_date)
except (ValueError, AttributeError):
# If parsing fails, treat as None
return (1, 0) if self.sort_direction == "desc" else (1, float('inf'))
return (0, value)
# For numeric fields, ensure we can compare
return (0, value)
# Sort the homes
reverse = (self.sort_direction == "desc")
sorted_homes = sorted(homes, key=get_sort_key, reverse=reverse)
return sorted_homes
@retry(

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@@ -1,5 +1,6 @@
from __future__ import annotations
import pandas as pd
import warnings
from datetime import datetime
from .core.scrapers.models import Property, ListingType, Advertisers
from .exceptions import InvalidListingType, InvalidDate
@@ -182,6 +183,36 @@ def validate_limit(limit: int) -> None:
raise ValueError("Property limit must be between 1 and 10,000.")
def validate_offset(offset: int, limit: int = 10000) -> None:
"""Validate offset parameter for pagination.
Args:
offset: Starting position for results pagination
limit: Maximum number of results to fetch
Raises:
ValueError: If offset is invalid or if offset + limit exceeds API limit
"""
if offset is not None and offset < 0:
raise ValueError("Offset must be non-negative (>= 0).")
# Check if offset + limit exceeds API's hard limit of 10,000
if offset is not None and limit is not None and (offset + limit) > 10000:
raise ValueError(
f"offset ({offset}) + limit ({limit}) = {offset + limit} exceeds API maximum of 10,000. "
f"The API cannot return results beyond position 10,000. "
f"To fetch more results, narrow your search."
)
# Warn if offset is not a multiple of 200 (API page size)
if offset is not None and offset > 0 and offset % 200 != 0:
warnings.warn(
f"Offset should be a multiple of 200 (page size) for optimal performance. "
f"Using offset {offset} may result in less efficient pagination.",
UserWarning
)
def validate_datetime(datetime_str: str | None) -> None:
"""Validate ISO 8601 datetime format."""
if not datetime_str:

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@@ -1,6 +1,6 @@
[tool.poetry]
name = "homeharvest"
version = "0.7.1"
version = "0.7.2"
description = "Real estate scraping library"
authors = ["Zachary Hampton <zachary@bunsly.com>", "Cullen Watson <cullen@bunsly.com>"]
homepage = "https://github.com/ZacharyHampton/HomeHarvest"

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@@ -870,66 +870,111 @@ def test_combined_filters():
def test_sorting_by_price():
"""Test sorting by list_price - note API sorting may not be perfect"""
"""Test sorting by list_price with actual sort order validation"""
# Sort ascending (cheapest first)
# Sort ascending (cheapest first) with multi-page limit to test concatenation
result_asc = scrape_property(
location="Orlando, FL",
listing_type="for_sale",
sort_by="list_price",
sort_direction="asc",
limit=20
limit=250 # Multi-page to test concatenation logic
)
assert result_asc is not None and len(result_asc) > 0
# Verify ascending sort order (allow for None/NA values at the end)
prices_asc = result_asc["list_price"].dropna().tolist()
assert len(prices_asc) > 0, "No properties with prices found"
assert prices_asc == sorted(prices_asc), f"Prices not in ascending order: {prices_asc[:10]}"
# Sort descending (most expensive first)
result_desc = scrape_property(
location="San Antonio, TX",
listing_type="for_sale",
sort_by="list_price",
sort_direction="desc",
limit=20
limit=250 # Multi-page to test concatenation logic
)
assert result_desc is not None and len(result_desc) > 0
# Note: Realtor API sorting may not be perfectly reliable for all search types
# The test ensures the sort parameters don't cause errors, actual sort order may vary
# Verify descending sort order (allow for None/NA values at the end)
prices_desc = result_desc["list_price"].dropna().tolist()
assert len(prices_desc) > 0, "No properties with prices found"
assert prices_desc == sorted(prices_desc, reverse=True), f"Prices not in descending order: {prices_desc[:10]}"
def test_sorting_by_date():
"""Test sorting by list_date - note API sorting may not be perfect"""
"""Test sorting by list_date with actual sort order validation"""
result = scrape_property(
# Test descending (newest first) with multi-page limit
result_desc = scrape_property(
location="Columbus, OH",
listing_type="for_sale",
sort_by="list_date",
sort_direction="desc", # Newest first
limit=20
limit=250 # Multi-page to test concatenation logic
)
assert result is not None and len(result) > 0
assert result_desc is not None and len(result_desc) > 0
# Test ensures sort parameter doesn't cause errors
# Note: Realtor API sorting may not be perfectly reliable for all search types
# Verify descending sort order (allow for None/NA values at the end)
dates_desc = result_desc["list_date"].dropna().tolist()
assert len(dates_desc) > 0, "No properties with dates found"
assert dates_desc == sorted(dates_desc, reverse=True), f"Dates not in descending order (newest first): {dates_desc[:10]}"
# Test ascending (oldest first)
result_asc = scrape_property(
location="Columbus, OH",
listing_type="for_sale",
sort_by="list_date",
sort_direction="asc", # Oldest first
limit=250
)
assert result_asc is not None and len(result_asc) > 0
# Verify ascending sort order
dates_asc = result_asc["list_date"].dropna().tolist()
assert len(dates_asc) > 0, "No properties with dates found"
assert dates_asc == sorted(dates_asc), f"Dates not in ascending order (oldest first): {dates_asc[:10]}"
def test_sorting_by_sqft():
"""Test sorting by square footage - note API sorting may not be perfect"""
"""Test sorting by square footage with actual sort order validation"""
result = scrape_property(
# Test descending (largest first) with multi-page limit
result_desc = scrape_property(
location="Indianapolis, IN",
listing_type="for_sale",
sort_by="sqft",
sort_direction="desc", # Largest first
limit=20
limit=250 # Multi-page to test concatenation logic
)
assert result is not None and len(result) > 0
assert result_desc is not None and len(result_desc) > 0
# Test ensures sort parameter doesn't cause errors
# Note: Realtor API sorting may not be perfectly reliable for all search types
# Verify descending sort order (allow for None/NA values at the end)
sqfts_desc = result_desc["sqft"].dropna().tolist()
assert len(sqfts_desc) > 0, "No properties with sqft found"
assert sqfts_desc == sorted(sqfts_desc, reverse=True), f"Square footages not in descending order: {sqfts_desc[:10]}"
# Test ascending (smallest first)
result_asc = scrape_property(
location="Indianapolis, IN",
listing_type="for_sale",
sort_by="sqft",
sort_direction="asc", # Smallest first
limit=250
)
assert result_asc is not None and len(result_asc) > 0
# Verify ascending sort order
sqfts_asc = result_asc["sqft"].dropna().tolist()
assert len(sqfts_asc) > 0, "No properties with sqft found"
assert sqfts_asc == sorted(sqfts_asc), f"Square footages not in ascending order: {sqfts_asc[:10]}"
def test_filter_validation_errors():