滤波器

FilterExpression （筛选表达式）

class FilterExpression(_filter=None, operator=None, left=None, right=None)

FilterExpression 是 RedisVL 中筛选器的逻辑组合。

FilterExpressions 可以使用 & 和 |要创建的运算符 计算结果为 Redis 查询语言的复杂表达式。

这提供了一个界面，用户可以通过该界面创建复杂的查询 无需了解 Redis 查询语言。

from redisvl.query.filter import Tag, Num

brand_is_nike = Tag("brand") == "nike"
price_is_over_100 = Num("price") < 100
f = brand_is_nike & price_is_over_100

print(str(f))

>> (@brand:{nike} @price:[-inf (100)])

This can be combined with the VectorQuery class to create a query:

from redisvl.query import VectorQuery

v = VectorQuery(
    vector=[0.1, 0.1, 0.5, ...],
    vector_field_name="product_embedding",
    return_fields=["product_id", "brand", "price"],
    filter_expression=f,
)

NOTE

Filter expressions are typically not called directly. Instead they are built by combining filter statements using the & and | operators.

Tag

class Tag(field)

A Tag filter can be applied to Tag fields

  • Parameters: field (str)

__eq__(other)

Create a Tag equality filter expression.

  • Parameters: other (Union [ List [ str ] , str ]) – The tag(s) to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Tag

f = Tag("brand") == "nike"

__ne__(other)

Create a Tag inequality filter expression.

  • Parameters: other (Union [ List [ str ] , str ]) – The tag(s) to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Tag
f = Tag("brand") != "nike"

__str__()

Return the Redis Query string for the Tag filter

  • Return type: str

Text

class Text(field)

A Text is a FilterField representing a text field in a Redis index.

  • Parameters: field (str)

__eq__(other)

Create a Text equality filter expression. These expressions yield filters that enforce an exact match on the supplied term(s).

  • Parameters: other (str) – The text value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Text

f = Text("job") == "engineer"

__mod__(other)

Create a Text “LIKE” filter expression. A flexible expression that yields filters that can use a variety of additional operators like wildcards (*), fuzzy matches (%%), or combinatorics (|) of the supplied term(s).

  • Parameters: other (str) – The text value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Text

f = Text("job") % "engine*"         # suffix wild card match
f = Text("job") % "%%engine%%"      # fuzzy match w/ Levenshtein Distance
f = Text("job") % "engineer|doctor" # contains either term in field
f = Text("job") % "engineer doctor" # contains both terms in field

__ne__(other)

Create a Text inequality filter expression. These expressions yield negated filters on exact matches on the supplied term(s). Opposite of an equality filter expression.

  • Parameters: other (str) – The text value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Text

f = Text("job") != "engineer"

__str__()

Return the Redis Query string for the Text filter

  • Return type: str

Num

class Num(field)

A Num is a FilterField representing a numeric field in a Redis index.

  • Parameters: field (str)

__eq__(other)

Create a Numeric equality filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num
f = Num("zipcode") == 90210

__ge__(other)

Create a Numeric greater than or equal to filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num

f = Num("age") >= 18

__gt__(other)

Create a Numeric greater than filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num

f = Num("age") > 18

__le__(other)

Create a Numeric less than or equal to filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num

f = Num("age") <= 18

__lt__(other)

Create a Numeric less than filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num

f = Num("age") < 18

__ne__(other)

Create a Numeric inequality filter expression.

  • Parameters: other (int) – The value to filter on.
  • Return type: FilterExpression
from redisvl.query.filter import Num

f = Num("zipcode") != 90210

__str__()

Return the Redis Query string for the Numeric filter

  • Return type: str

Geo

class Geo(field)

A Geo is a FilterField representing a geographic (lat/lon) field in a Redis index.

  • Parameters: field (str)

__eq__(other)

Create a geographic filter within a specified GeoRadius.

from redisvl.query.filter import Geo, GeoRadius

f = Geo("location") == GeoRadius(-122.4194, 37.7749, 1, unit="m")

__ne__(other)

Create a geographic filter outside of a specified GeoRadius.

from redisvl.query.filter import Geo, GeoRadius

f = Geo("location") != GeoRadius(-122.4194, 37.7749, 1, unit="m")

__str__()

Return the Redis Query string for the Geo filter

  • Return type: str

GeoRadius

class GeoRadius(longitude, latitude, radius=1, unit='km')

A GeoRadius is a GeoSpec representing a geographic radius.

Create a GeoRadius specification (GeoSpec)

  • Parameters:
    • longitude (float) – The longitude of the center of the radius.
    • latitude (float) – The latitude of the center of the radius.
    • radius (int , optional) – The radius of the circle. Defaults to 1.
    • unit (str , optional) – The unit of the radius. Defaults to “km”.
  • Raises: ValueError – If the unit is not one of “m”, “km”, “mi”, or “ft”.

__init__(longitude, latitude, radius=1, unit='km')

Create a GeoRadius specification (GeoSpec)

  • Parameters:
    • longitude (float) – The longitude of the center of the radius.
    • latitude (float) – The latitude of the center of the radius.
    • radius (int , optional) – The radius of the circle. Defaults to 1.
    • unit (str , optional) – The unit of the radius. Defaults to “km”.
  • Raises: ValueError – If the unit is not one of “m”, “km”, “mi”, or “ft”.
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