CollectionType¶

class lsst.daf.butler.CollectionType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)¶

Bases: IntEnum

Enumeration used to label different types of collections.

Attributes Summary

`CALIBRATION`	A `CALIBRATION` collection operates like a `TAGGED` collection, but also associates each dataset with a validity range as well.
`CHAINED`	A `CHAINED` collection is simply an ordered list of other collections to be searched.
`RUN`	A `RUN` collection (also just called a 'run') is the initial collection a dataset is inserted into and the only one it can never be removed from.
`TAGGED`	Datasets can be associated with and removed from `TAGGED` collections arbitrarily.
`denominator`	the denominator of a rational number in lowest terms
`imag`	the imaginary part of a complex number
`numerator`	the numerator of a rational number in lowest terms
`real`	the real part of a complex number

Methods Summary

`as_integer_ratio`(/)	Return integer ratio.
`bit_count`(/)	Number of ones in the binary representation of the absolute value of self.
`bit_length`(/)	Number of bits necessary to represent self in binary.
`conjugate`	Returns self, the complex conjugate of any int.
`from_bytes`(/, bytes[, byteorder, signed])	Return the integer represented by the given array of bytes.
`to_bytes`(/[, length, byteorder, signed])	Return an array of bytes representing an integer.

Attributes Documentation

CALIBRATION = 4¶

A CALIBRATION collection operates like a TAGGED collection, but also associates each dataset with a validity range as well. Queries against calibration collections must include a timestamp as an input.

It is difficult (perhaps impossible) to enforce a constraint that there be one dataset with a particular dataset type and data ID at any particular timestamp in the database, so higher-level tools that populate calibration collections are expected to maintain that invariant instead.

CHAINED = 3¶: A CHAINED collection is simply an ordered list of other collections to be searched. These may include other CHAINED collections.

RUN = 1¶

A RUN collection (also just called a ‘run’) is the initial collection a dataset is inserted into and the only one it can never be removed from.

Within a particular run, there may only be one dataset with a particular dataset type and data ID.

TAGGED = 2¶

Datasets can be associated with and removed from TAGGED collections arbitrarily.

Within a particular tagged collection, there may only be one dataset with a particular dataset type and data ID.

denominator¶: the denominator of a rational number in lowest terms

imag¶: the imaginary part of a complex number

numerator¶: the numerator of a rational number in lowest terms

real¶: the real part of a complex number

Methods Documentation

as_integer_ratio(/)¶

Return integer ratio.

Return a pair of integers, whose ratio is exactly equal to the original int and with a positive denominator.

>>> (10).as_integer_ratio()
(10, 1)
>>> (-10).as_integer_ratio()
(-10, 1)
>>> (0).as_integer_ratio()
(0, 1)

bit_count(/)¶

Number of ones in the binary representation of the absolute value of self.

Also known as the population count.

>>> bin(13)
'0b1101'
>>> (13).bit_count()
3

bit_length(/)¶

Number of bits necessary to represent self in binary.

>>> bin(37)
'0b100101'
>>> (37).bit_length()
6

conjugate()¶: Returns self, the complex conjugate of any int.

from_bytes(/, bytes, byteorder='big', *, signed=False)¶

Return the integer represented by the given array of bytes.

bytes: Holds the array of bytes to convert. The argument must either support the buffer protocol or be an iterable object producing bytes. Bytes and bytearray are examples of built-in objects that support the buffer protocol.
byteorder: The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.
signed: Indicates whether two’s complement is used to represent the integer.

to_bytes(/, length=1, byteorder='big', *, signed=False)¶

Return an array of bytes representing an integer.

length: Length of bytes object to use. An OverflowError is raised if the integer is not representable with the given number of bytes. Default is length 1.
byteorder: The byte order used to represent the integer. If byteorder is ‘big’, the most significant byte is at the beginning of the byte array. If byteorder is ‘little’, the most significant byte is at the end of the byte array. To request the native byte order of the host system, use `sys.byteorder’ as the byte order value. Default is to use ‘big’.
signed: Determines whether two’s complement is used to represent the integer. If signed is False and a negative integer is given, an OverflowError is raised.

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CollectionType¶