QUuid¶
Detailed Description¶
The PySide.QtCore.QUuid class stores a Universally Unique Identifier (UUID).
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 PySide.QtCore.QUuid.variant() to discover which type of UUID an instance of PySide.QtCore.QUuid contains. It extracts the three most signifcant bits of byte 8 of the 16 bytes. In PySide.QtCore.QUuid , byte 8 is QUuid::data4[0] . If you create instances of PySide.QtCore.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 PySide.QtCore.QUuid.variant() returns QUuid.DCE , the UUID also contains a version field in the four most significant bits of QUuid::data3 , and you can call PySide.QtCore.QUuid.version() to discover which version your PySide.QtCore.QUuid contains. If you create instances of PySide.QtCore.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 Name 0 1 0 0 Random 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 PySide.QtCore.QUuid.createUuid() . UUIDs generated by PySide.QtCore.QUuid.createUuid() are of the random type. Their QUuid.Version bits are set to QUuid.Random , and their QUuid.Variant bits are set to QUuid.DCE . The rest of the UUID is composed of random numbers. Theoretically, this means there is a small chance that a UUID generated by PySide.QtCore.QUuid.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 PySide.QtCore.QUuid.createUuid() function. They can be converted to a string with PySide.QtCore.QUuid.toString() . UUIDs have a PySide.QtCore.QUuid.variant() and a PySide.QtCore.QUuid.version() , and null UUIDs return true from PySide.QtCore.QUuid.isNull() .
- class PySide.QtCore.QUuid¶
- class PySide.QtCore.QUuid(arg__1)
- class PySide.QtCore.QUuid(QUuid)
- class PySide.QtCore.QUuid(arg__1)
- class PySide.QtCore.QUuid(l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8)
Parameters: - b1 – PySide.QtCore.uchar
- b2 – PySide.QtCore.uchar
- b3 – PySide.QtCore.uchar
- b4 – PySide.QtCore.uchar
- QUuid – PySide.QtCore.QUuid
- l – PySide.QtCore.uint
- b5 – PySide.QtCore.uchar
- b6 – PySide.QtCore.uchar
- b7 – PySide.QtCore.uchar
- b8 – PySide.QtCore.uchar
- arg__1 – unicode
- w1 – PySide.QtCore.ushort
- w2 – PySide.QtCore.ushort
Creates the null UUID. PySide.QtCore.QUuid.toString() will output the null UUID as “{00000000-0000-0000-0000-000000000000}”.
Creates a PySide.QtCore.QUuid object from the string text , which must be formatted as five hex fields separated by ‘-‘, e.g., “{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}” where ‘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 PySide.QtCore.QUuid.toString() for an explanation of how the five hex fields map to the public data members in PySide.QtCore.QUuid .
See also
PySide.QtCore.QUuid.toString() PySide.QtCore.QUuid.QUuid()
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)
- PySide.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 PySide.QtCore.QUuid QUuid.Microsoft Reserved for Microsoft backward compatibility (GUID) QUuid.Reserved Reserved for future definition
- PySide.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 QUuid.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.Random Random-based, by using random numbers for all sections
- PySide.QtCore.QUuid.__reduce__()¶
Return type: PyObject
- PySide.QtCore.QUuid.__repr__()¶
Return type: PyObject
- static PySide.QtCore.QUuid.createUuid()¶
Return type: PySide.QtCore.QUuid On any platform other than Windows, this function returns a new UUID with variant QUuid.DCE and version QUuid.Random . If the /dev/urandom device exists, then the numbers used to construct the UUID will be of cryptographic quality, which will make the UUID unique. Otherwise, the numbers of the UUID will be obtained from the local pseudo-random number generator ( qrand() , which is seeded by qsrand() ) which is usually not of cryptograhic quality, which means that the UUID can’t be guaranteed to be unique.
On a Windows platform, a GUID is generated, which almost certainly will be unique, on this or any other system, networked or not.
- PySide.QtCore.QUuid.isNull()¶
Return type: PySide.QtCore.bool Returns true if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns false.
- PySide.QtCore.QUuid.__ne__(orig)¶
Parameters: orig – PySide.QtCore.QUuid Return type: PySide.QtCore.bool Returns true if this PySide.QtCore.QUuid and the otherPySide.QtCore.QUuid are different; otherwise returns false.
- PySide.QtCore.QUuid.__lt__(other)¶
Parameters: other – PySide.QtCore.QUuid Return type: PySide.QtCore.bool Returns true if this PySide.QtCore.QUuid has the same variant field as the otherPySide.QtCore.QUuid and is lexicographically before the otherPySide.QtCore.QUuid . If the otherPySide.QtCore.QUuid has a different variant field, the return value is determined by comparing the two variants .
See also
- PySide.QtCore.QUuid.__eq__(orig)¶
Parameters: orig – PySide.QtCore.QUuid Return type: PySide.QtCore.bool Returns true if this PySide.QtCore.QUuid and the otherPySide.QtCore.QUuid are identical; otherwise returns false.
- PySide.QtCore.QUuid.__gt__(other)¶
Parameters: other – PySide.QtCore.QUuid Return type: PySide.QtCore.bool Returns true if this PySide.QtCore.QUuid has the same variant field as the otherPySide.QtCore.QUuid and is lexicographically after the otherPySide.QtCore.QUuid . If the otherPySide.QtCore.QUuid has a different variant field, the return value is determined by comparing the two variants .
See also
- PySide.QtCore.QUuid.toString()¶
Return type: unicode Returns the string representation of this PySide.QtCore.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 PySide.QtCore.QUuid as follows:
Field # Source 1 data1 2 data2 3 data3 4 data4[0] .. data4[1] 5 data4[2] .. data4[7]
- PySide.QtCore.QUuid.variant()¶
Return type: PySide.QtCore.QUuid.Variant Returns the value in the variant field of the UUID. If the return value is QUuid.DCE , call PySide.QtCore.QUuid.version() to see which layout it uses. The null UUID is considered to be of an unknown variant.
See also
- PySide.QtCore.QUuid.version()¶
Return type: PySide.QtCore.QUuid.Version Returns the version field of the UUID, if the UUID’s variant field is QUuid.DCE . Otherwise it returns QUuid.VerUnknown .
See also
