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cassandra.util - Utilities

class cassandra.util.Date

Idealized date: year, month, day

Offers wider year range than datetime.date. For Dates that cannot be represented as a datetime.date (because datetime.MINYEAR, datetime.MAXYEAR), this type falls back to printing days_from_epoch offset.

Initializer value can be:

  • integer_type: absolute days from epoch (1970, 1, 1). Can be negative.

  • datetime.date: built-in date

  • string_type: a string time of the form “yyyy-mm-dd”

date

Return a built-in datetime.date for Dates falling in the years [datetime.MINYEAR, datetime.MAXYEAR]

ValueError is raised for Dates outside this range.

property seconds

Absolute seconds from epoch (can be negative)

class cassandra.util.DateRange(lower_bound=None, upper_bound=None, value=None)

DSE DateRange Type

lower_bound

DateRangeBound representing the lower bound of a bounded range.

upper_bound

DateRangeBound representing the upper bound of a bounded range.

value

DateRangeBound representing the value of a single-value range.

As noted in its documentation, DateRangeBound uses a millisecond offset from the UNIX epoch to allow DateRange to represent values datetime.datetime cannot. For such values, string representions will show this offset rather than the CQL representation.

Parameters
class cassandra.util.DateRangeBound(value, precision)

Represents a single date value and its precision for DateRange.

milliseconds

Integer representing milliseconds since the UNIX epoch. May be negative.

precision

String representing the precision of a bound. Must be a valid DateRangePrecision member.

DateRangeBound uses a millisecond offset from the UNIX epoch to allow DateRange to represent values datetime.datetime cannot. For such values, string representions will show this offset rather than the CQL representation.

Parameters
  • value – a value representing ms since the epoch. Accepts an integer or a datetime.

  • precision – a string representing precision

datetime

Return milliseconds as a datetime.datetime if possible. Raises an OverflowError if the value is out of range.

classmethod from_value(value)

Construct a new DateRangeBound from a given value. If possible, use the value[‘milliseconds’] and value[‘precision’] keys of the argument. Otherwise, use the argument as a (milliseconds, precision) iterable.

Parameters

value – a dictlike or iterable object

class cassandra.util.DateRangePrecision

An “enum” representing the valid values for DateRange.precision.

class cassandra.util.Distance

Represents a Distance geometry for DSE

from_wkt

Parse a Distance geometry from a wkt string and return a new Distance object.

class cassandra.util.Duration

Cassandra Duration Type

class cassandra.util.LineString

Represents a linestring geometry for DSE

‘coords`: a sequence of (x, y) coordinates of points in the linestring

from_wkt

Parse a LineString geometry from a wkt string and return a new LineString object.

class cassandra.util.OrderedMap

An ordered map that accepts non-hashable types for keys. It also maintains the insertion order of items, behaving as OrderedDict in that regard. These maps are constructed and read just as normal mapping types, exept that they may contain arbitrary collections and other non-hashable items as keys:

>>> od = OrderedMap([({'one': 1, 'two': 2}, 'value'),
...                  ({'three': 3, 'four': 4}, 'value2')])
>>> list(od.keys())
[{'two': 2, 'one': 1}, {'three': 3, 'four': 4}]
>>> list(od.values())
['value', 'value2']

These constructs are needed to support nested collections in Cassandra 2.1.3+, where frozen collections can be specified as parameters to others:

CREATE TABLE example (
    ...
    value map<frozen<map<int, int>>, double>
    ...
)

This class derives from the (immutable) Mapping API. Objects in these maps are not intended be modified.

class cassandra.util.OrderedMapSerializedKey
class cassandra.util.Point

Represents a point geometry for DSE

from_wkt

Parse a Point geometry from a wkt string and return a new Point object.

class cassandra.util.Polygon

Represents a polygon geometry for DSE

‘exterior`: a sequence of (x, y) coordinates of points in the linestring interiors: None, or a sequence of sequences or (x, y) coordinates of points describing interior linear rings

from_wkt

Parse a Polygon geometry from a wkt string and return a new Polygon object.

class cassandra.util.SortedSet

A sorted set based on sorted list

A sorted set implementation is used in this case because it does not require its elements to be immutable/hashable.

#Not implemented: update functions, inplace operators

class cassandra.util.Time

Idealized time, independent of day.

Up to nanosecond resolution

Initializer value can be:

  • integer_type: absolute nanoseconds in the day

  • datetime.time: built-in time

  • string_type: a string time of the form “HH:MM:SS[.mmmuuunnn]”

property hour

The hour component of this time (0-23)

property minute

The minute component of this time (0-59)

property nanosecond

The fractional seconds component of the time, in nanoseconds

property second

The second component of this time (0-59)

time

Return a built-in datetime.time (nanosecond precision truncated to micros).

class cassandra.util.Version

Internal minimalist class to compare versions. A valid version is: <int>.<int>.<int>.<int or str>.

TODO: when python2 support is removed, use packaging.version.

cassandra.util.datetime_from_timestamp

Creates a timezone-agnostic datetime from timestamp (in seconds) in a consistent manner. Works around a Windows issue with large negative timestamps (PYTHON-119), and rounding differences in Python 3.4 (PYTHON-340).

Parameters

timestamp – a unix timestamp, in seconds

cassandra.util.datetime_from_uuid1

Creates a timezone-agnostic datetime from the timestamp in the specified type-1 UUID.

Parameters

uuid_arg – a version 1 UUID

cassandra.util.max_uuid_from_time

Generates the maximum TimeUUID (type 1) for a given timestamp, as compared by Cassandra.

See uuid_from_time() for argument and return types.

cassandra.util.min_uuid_from_time

Generates the minimum TimeUUID (type 1) for a given timestamp, as compared by Cassandra.

See uuid_from_time() for argument and return types.

cassandra.util.ms_timestamp_from_datetime

Converts a datetime to a timestamp expressed in milliseconds.

Parameters

dt – a datetime.datetime

cassandra.util.sortedset

alias of cassandra.util.SortedSet

cassandra.util.unix_time_from_uuid1

Converts a version 1 uuid.UUID to a timestamp with the same precision as time.time() returns. This is useful for examining the results of queries returning a v1 UUID.

Parameters

uuid_arg – a version 1 UUID

cassandra.util.utc_datetime_from_ms_timestamp

Creates a UTC datetime from a timestamp in milliseconds. See datetime_from_timestamp().

Raises an OverflowError if the timestamp is out of range for datetime.

Parameters

timestamp – timestamp, in milliseconds

cassandra.util.uuid_from_time

Converts a datetime or timestamp to a type 1 uuid.UUID.

Parameters
  • time_arg – The time to use for the timestamp portion of the UUID. This can either be a datetime object or a timestamp in seconds (as returned from time.time()).

  • node (long) – None integer for the UUID (up to 48 bits). If not specified, this field is randomized.

  • clock_seq (int) – Clock sequence field for the UUID (up to 14 bits). If not specified, a random sequence is generated.

Return type

uuid.UUID