QUuid

The QUuid class stores a Universally Unique Identifier (UUID). More…

Inheritance diagram of PySide2.QtCore.QUuid

Synopsis

Functions

Static functions

Detailed Description

Using U niversally U nique ID entifiers (UUID) is a standard way to uniquely identify entities in a distributed computing environment. A UUID is a 16-byte (128-bit) number generated by some algorithm that is meant to guarantee that the UUID will be unique in the distributed computing environment where it is used. The acronym GUID is often used instead, G lobally U nique ID entifiers, but it refers to the same thing.

Actually, the GUID is one variant of UUID. Multiple variants are in use. Each UUID contains a bit field that specifies which type (variant) of UUID it is. Call variant() to discover which type of UUID an instance of QUuid contains. It extracts the three most significant bits of byte 8 of the 16 bytes. In QUuid , byte 8 is QUuid::data4[0] . If you create instances of QUuid using the constructor that accepts all the numeric values as parameters, use the following table to set the three most significant bits of parameter b1 , which becomes QUuid::data4[0] and contains the variant field in its three most significant bits. In the table, ‘x’ means don’t care .

msb0

msb1

msb2

Variant

0

x

x

NCS (Network Computing System)

1

0

x

DCE (Distributed Computing Environment)

1

1

0

Microsoft (GUID)

1

1

1

Reserved for future expansion

If variant() returns DCE , the UUID also contains a version field in the four most significant bits of QUuid::data3 , and you can call version() to discover which version your QUuid contains. If you create instances of QUuid using the constructor that accepts all the numeric values as parameters, use the following table to set the four most significant bits of parameter w2 , which becomes QUuid::data3 and contains the version field in its four most significant bits.

msb0

msb1

msb2

msb3

Version

0

0

0

1

Time

0

0

1

0

Embedded POSIX

0

0

1

1

Md5(Name)

0

1

0

0

Random

0

1

0

1

Sha1

The field layouts for the DCE versions listed in the table above are specified in the Network Working Group UUID Specification.

Most platforms provide a tool for generating new UUIDs, e.g. uuidgen and guidgen . You can also use createUuid() . UUIDs generated by createUuid() are of the random type. Their Version bits are set to Random , and their Variant bits are set to DCE . The rest of the UUID is composed of random numbers. Theoretically, this means there is a small chance that a UUID generated by createUuid() will not be unique. But it is a very small chance.

UUIDs can be constructed from numeric values or from strings, or using the static createUuid() function. They can be converted to a string with toString() . UUIDs have a variant() and a version() , and null UUIDs return true from isNull() .

class QUuid

QUuid(arg__1)

QUuid(arg__1)

QUuid(arg__1)

QUuid(l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8)

param b8

uchar

param l

uint

param arg__1

QByteArray

param b1

uchar

param b2

uchar

param b3

uchar

param b4

uchar

param b5

uchar

param w1

ushort

param b6

uchar

param w2

ushort

param b7

uchar

Creates the null UUID. toString() will output the null UUID as “{00000000-0000-0000-0000-000000000000}”.

Creates a UUID with the value specified by the parameters, l , w1 , w2 , b1 , b2 , b3 , b4 , b5 , b6 , b7 , b8 .

Example:

# {67C8770B-44F1-410A-AB9A-F9B5446F13EE}
IID_MyInterface = QUuid(0x67c8770b, 0x44f1, 0x410a, 0xab, 0x9a, 0xf9, 0xb5, 0x44, 0x6f, 0x13, 0xee)
PySide2.QtCore.QUuid.Variant

This enum defines the values used in the variant field of the UUID. The value in the variant field determines the layout of the 128-bit value.

Constant

Description

QUuid.VarUnknown

Variant is unknown

QUuid.NCS

Reserved for NCS (Network Computing System) backward compatibility

QUuid.DCE

Distributed Computing Environment, the scheme used by QUuid

QUuid.Microsoft

Reserved for Microsoft backward compatibility (GUID)

QUuid.Reserved

Reserved for future definition
PySide2.QtCore.QUuid.Version

This enum defines the values used in the version field of the UUID. The version field is meaningful only if the value in the variant field is DCE .

Constant

Description

QUuid.VerUnknown

Version is unknown

QUuid.Time

Time-based, by using timestamp, clock sequence, and MAC network card address (if available) for the node sections

QUuid.EmbeddedPOSIX

DCE Security version, with embedded POSIX UUIDs

QUuid.Name

Name-based, by using values from a name for all sections

QUuid.Md5

Alias for Name

QUuid.Random

Random-based, by using random numbers for all sections

QUuid.Sha1
PySide2.QtCore.QUuid.StringFormat

This enum is used by toString () to control the formatting of the string representation. The possible values are:

Constant

Description

QUuid.WithBraces

The default, toString() will return five hex fields, separated by dashes and surrounded by braces. Example: {00000000-0000-0000-0000-000000000000}.

QUuid.WithoutBraces

Only the five dash-separated fields, without the braces. Example: 00000000-0000-0000-0000-000000000000.

QUuid.Id128

Only the hex digits, without braces or dashes. Note that QUuid cannot parse this back again as input.

New in version 5.11.

PySide2.QtCore.QUuid.__reduce__()
Return type

PyObject

PySide2.QtCore.QUuid.__repr__()
Return type

PyObject

static PySide2.QtCore.QUuid.createUuid()
Return type

QUuid

On any platform other than Windows, this function returns a new UUID with variant DCE and version Random . On Windows, a GUID is generated using the Windows API and will be of the type that the API decides to create.

See also

variant() version()

static PySide2.QtCore.QUuid.createUuidV3(ns, baseData)
Parameters
Return type

QUuid

static PySide2.QtCore.QUuid.createUuidV3(ns, baseData)
Parameters

  • ns – QUuid

  • baseData – unicode

Return type

QUuid

static PySide2.QtCore.QUuid.createUuidV5(ns, baseData)
Parameters
Return type

QUuid

static PySide2.QtCore.QUuid.createUuidV5(ns, baseData)
Parameters

  • ns – QUuid

  • baseData – unicode

Return type

QUuid

static PySide2.QtCore.QUuid.fromRfc4122(arg__1)
Parameters

arg__1 – QByteArray

Return type

QUuid

Creates a QUuid object from the binary representation of the UUID, as specified by RFC 4122 section 4.1.2. See toRfc4122() for a further explanation of the order of bytes required.

The byte array accepted is NOT a human readable format.

If the conversion fails, a null UUID is created.

See also

toRfc4122() QUuid()

PySide2.QtCore.QUuid.isNull()
Return type

bool

Returns true if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns false .

PySide2.QtCore.QUuid.__ne__(orig)
Parameters

orig – QUuid

Return type

bool

PySide2.QtCore.QUuid.__lt__(other)
Parameters

other – QUuid

Return type

bool

PySide2.QtCore.QUuid.__le__(rhs)
Parameters

rhs – QUuid

Return type

bool

PySide2.QtCore.QUuid.__eq__(orig)
Parameters

orig – QUuid

Return type

bool

PySide2.QtCore.QUuid.__gt__(other)
Parameters

other – QUuid

Return type

bool

Returns true if this QUuid has the same variant field as the other QUuid and is lexicographically after the other QUuid . If the other QUuid has a different variant field, the return value is determined by comparing the two variants .

See also

variant()

PySide2.QtCore.QUuid.__ge__(rhs)
Parameters

rhs – QUuid

Return type

bool

PySide2.QtCore.QUuid.toByteArray()
Return type

QByteArray

Returns the binary representation of this QUuid . The byte array is formatted as five hex fields separated by ‘-‘ and enclosed in curly braces, i.e., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where ‘x’ is a hex digit. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

Field #

Source

1

data1

2

data2

3

data3

4

data4[0] .. data4[1]

5

data4[2] .. data4[7]
PySide2.QtCore.QUuid.toByteArray(mode)
Parameters

mode – StringFormat

Return type

QByteArray

Returns the string representation of this QUuid , with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

Field #

Source

1

data1

2

data2

3

data3

4

data4[0] .. data4[1]

5

data4[2] .. data4[7]
PySide2.QtCore.QUuid.toRfc4122()
Return type

QByteArray

Returns the binary representation of this QUuid . The byte array is in big endian format, and formatted according to RFC 4122, section 4.1.2 - “Layout and byte order”.

The order is as follows:

Field #

Source

1

data1

2

data2

3

data3

4

data4[0] .. data4[7]
PySide2.QtCore.QUuid.toString()
Return type

unicode

Returns the string representation of this QUuid . The string is formatted as five hex fields separated by ‘-‘ and enclosed in curly braces, i.e., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where ‘x’ is a hex digit. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

Field #

Source

1

data1

2

data2

3

data3

4

data4[0] .. data4[1]

5

data4[2] .. data4[7]
PySide2.QtCore.QUuid.toString(mode)
Parameters

mode – StringFormat

Return type

unicode

Returns the string representation of this QUuid , with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

Field #

Source

1

data1

2

data2

3

data3

4

data4[0] .. data4[1]

5

data4[2] .. data4[7]
PySide2.QtCore.QUuid.variant()
Return type

Variant

Returns the value in the variant field of the UUID. If the return value is DCE , call version() to see which layout it uses. The null UUID is considered to be of an unknown variant.

See also

version()

PySide2.QtCore.QUuid.version()
Return type

Version

Returns the version field of the UUID, if the UUID’s variant field is DCE . Otherwise it returns VerUnknown .

See also

variant()