`cassandra.util` - Utilities¶

cassandra.util.datetime_from_timestamp(timestamp)[source]¶

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.utc_datetime_from_ms_timestamp(timestamp)[source]¶

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.ms_timestamp_from_datetime(dt)[source]¶

Converts a datetime to a timestamp expressed in milliseconds.

Parameters: dt – a datetime.datetime

cassandra.util.unix_time_from_uuid1(uuid_arg)[source]¶

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.datetime_from_uuid1(uuid_arg)[source]¶

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

Parameters: uuid_arg – a version 1 UUID

cassandra.util.min_uuid_from_time(timestamp)[source]¶

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.max_uuid_from_time(timestamp)[source]¶

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.uuid_from_time(time_arg, node=None, clock_seq=None)[source]¶

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

cassandra.util.LOWEST_TIME_UUID = UUID('00000000-0000-1000-8080-808080808080')¶: The lowest possible TimeUUID, as sorted by Cassandra.

cassandra.util.HIGHEST_TIME_UUID = UUID('ffffffff-ffff-1fff-bf7f-7f7f7f7f7f7f')¶: The highest possible TimeUUID, as sorted by Cassandra.

class cassandra.util.SortedSet(iterable=())[source]¶

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

cassandra.util.sortedset¶: alias of cassandra.util.SortedSet

class cassandra.util.OrderedMap(*args, **kwargs)[source]¶

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(cass_type, protocol_version)[source]¶

class cassandra.util.Time(value)[source]¶

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 second¶: The second component of this time (0-59)

property nanosecond¶: The fractional seconds component of the time, in nanoseconds

time()[source]¶: Return a built-in datetime.time (nanosecond precision truncated to micros).

class cassandra.util.Date(value)[source]¶

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”

property seconds¶: Absolute seconds from epoch (can be negative)

date()[source]¶

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

ValueError is raised for Dates outside this range.

cassandra.util.inet_ntop(af, packed_ip) → string formatted IP address¶: Windows doesn’t have socket.inet_pton and socket.inet_ntop until Python 3.4 This is an alternative impl using ctypes, based on this win_inet_pton project: https://github.com/hickeroar/win_inet_pton

class cassandra.util.Point(x=nan, y=nan)[source]¶

Represents a point geometry for DSE

x = None¶: x coordinate of the point

y = None¶: y coordinate of the point

static from_wkt(s)[source]¶: Parse a Point geometry from a wkt string and return a new Point object.

class cassandra.util.LineString(coords=())[source]¶

Represents a linestring geometry for DSE

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

coords = None¶: Tuple of (x, y) coordinates in the linestring

static from_wkt(s)[source]¶: Parse a LineString geometry from a wkt string and return a new LineString object.

class cassandra.util.Polygon(exterior=(), interiors=None)[source]¶

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

exterior = None¶: _LinearRing representing the exterior of the polygon

interiors = None¶: Tuple of _LinearRings representing interior holes in the polygon

static from_wkt(s)[source]¶: Parse a Polygon geometry from a wkt string and return a new Polygon object.

class cassandra.util.Distance(x=nan, y=nan, radius=nan)[source]¶

Represents a Distance geometry for DSE

x = None¶: x coordinate of the center point

y = None¶: y coordinate of the center point

radius = None¶: radius to represent the distance from the center point

static from_wkt(s)[source]¶: Parse a Distance geometry from a wkt string and return a new Distance object.

class cassandra.util.Duration(months=0, days=0, nanoseconds=0)[source]¶: Cassandra Duration Type

class cassandra.util.DateRangePrecision[source]¶

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

YEAR = 'YEAR'¶

MONTH = 'MONTH'¶

DAY = 'DAY'¶

HOUR = 'HOUR'¶

MINUTE = 'MINUTE'¶

SECOND = 'SECOND'¶

MILLISECOND = 'MILLISECOND'¶

PRECISIONS = ('YEAR', 'MONTH', 'DAY', 'HOUR', 'MINUTE', 'SECOND', 'MILLISECOND')¶

class cassandra.util.DateRangeBound(value, precision)[source]¶

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()[source]¶: Return milliseconds as a datetime.datetime if possible. Raises an OverflowError if the value is out of range.

classmethod from_value(value)[source]¶

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

cassandra.util.OPEN_BOUND = DateRangeBound(milliseconds=None, precision=None)¶: Represents *, an open value or bound for DateRange.

class cassandra.util.DateRange(lower_bound=None, upper_bound=None, value=None)[source]¶

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

lower_bound – a DateRangeBound or object accepted by DateRangeBound.from_value() to be used as a lower_bound. Mutually exclusive with value. If upper_bound is specified and this is not, the lower_bound will be open.
upper_bound – a DateRangeBound or object accepted by DateRangeBound.from_value() to be used as a upper_bound. Mutually exclusive with value. If lower_bound is specified and this is not, the upper_bound will be open.
value – a DateRangeBound or object accepted by DateRangeBound.from_value() to be used as value. Mutually exclusive with lower_bound and lower_bound.

class cassandra.util.Version(version)[source]¶

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 - Utilities¶

`cassandra.util` - Utilities¶