class QUuid#

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

Inherited by: QBluetoothUuid

Synopsis#

Methods#

Static functions#

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description#

Using Universally Unique IDentifiers (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, Globally Unique IDentifiers, 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 very ` <http://en.wikipedia.org/wiki/Universally_Unique_Identifier#Random_UUID_probability_of_duplicates>`_ 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 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
class 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
class StringFormat#

This enum is used by toString (StringFormat) 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.
__init__(string)#
Parameters:

string – str

Creates a QUuid object from the string text, which must be formatted as five hex fields separated by ‘-’, e.g., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where each ‘x’ is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is created. See toString() for an explanation of how the five hex fields map to the public data members in QUuid .

Note

In Qt versions prior to 6.3, this constructor was an overload set consisting of QString , QByteArray and const char* instead of one constructor taking QAnyStringView .

See also

toString() QUuid()

__init__(l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8)
Parameters:

  • l – int

  • w1 – int

  • w2 – int

  • b1 – int

  • b2 – int

  • b3 – int

  • b4 – int

  • b5 – int

  • b6 – int

  • b7 – int

  • b8 – int

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

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)
__init__()

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

__reduce__()#
Return type:

object

__repr__()#
Return type:

object

static 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 createUuidV3(ns, baseData)#
Parameters:
Return type:

QUuid

This function returns a new UUID with variant DCE and version Md5 . ns is the namespace and baseData is the basic data as described by RFC 4122.

static createUuidV3(ns, baseData)
Parameters:

  • ns – QUuid

  • baseData – str

Return type:

QUuid

This function returns a new UUID with variant DCE and version Md5 . ns is the namespace and baseData is the basic data as described by RFC 4122.

static createUuidV5(ns, baseData)#
Parameters:
Return type:

QUuid

This function returns a new UUID with variant DCE and version Sha1 . ns is the namespace and baseData is the basic data as described by RFC 4122.

static createUuidV5(ns, baseData)
Parameters:

  • ns – QUuid

  • baseData – str

Return type:

QUuid

This function returns a new UUID with variant DCE and version Sha1 . ns is the namespace and baseData is the basic data as described by RFC 4122.

static fromBytes(bytes[, order=QSysInfo.BigEndian])#
Parameters:

  • bytes – void

  • order – Endian

Return type:

QUuid

Reads 128 bits (16 bytes) from bytes using byte order order and returns the QUuid corresponding to those bytes. This function does the same as fromRfc4122() if the byte order order is BigEndian .

See also

fromRfc4122()

static fromRfc4122(arg__1)#
Parameters:

arg__1 – QByteArrayView

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.

Note

In Qt versions prior to 6.3, this function took QByteArray , not QByteArrayView .

See also

toRfc4122() QUuid() fromBytes()

static fromString(string)#
Parameters:

string – str

Return type:

QUuid

Creates a QUuid object from the string string, which must be formatted as five hex fields separated by ‘-’, e.g., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where each ‘x’ is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is returned. See toString() for an explanation of how the five hex fields map to the public data members in QUuid .

Note

In Qt versions prior to 6.3, this function was an overload set consisting of QStringView and QLatin1StringView instead of one function taking QAnyStringView .

See also

toString() QUuid()

isNull()#
Return type:

bool

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

__ne__(orig)#
Parameters:

orig – QUuid

Return type:

bool

Returns true if this QUuid and the other QUuid are different; otherwise returns false.

__lt__(other)#
Parameters:

other – QUuid

Return type:

bool

Returns true if this QUuid has the same variant field as the other QUuid and is lexicographically before 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()

__le__(rhs)#
Parameters:

rhs – QUuid

Return type:

bool

Returns true if lhs has the same variant field as rhs and is lexicographically not after rhs. If rhs has a different variant field, the return value is determined by comparing the two variants .

See also

variant()

__eq__(orig)#
Parameters:

orig – QUuid

Return type:

bool

Returns true if this QUuid and the other QUuid are identical; otherwise returns false.

__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()

__ge__(rhs)#
Parameters:

rhs – QUuid

Return type:

bool

Returns true if lhs has the same variant field as rhs and is lexicographically not before rhs. If rhs has a different variant field, the return value is determined by comparing the two variants .

See also

variant()

toByteArray([mode=QUuid.StringFormat.WithBraces])#
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]
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]

The bytes in the byte array returned by this function contains the same binary content as toBytes() .

See also

toBytes()

toString([mode=QUuid.StringFormat.WithBraces])#
Parameters:

mode – StringFormat

Return type:

str

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]
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()

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()