772 lines
29 KiB
Python
772 lines
29 KiB
Python
r"""UUID objects (universally unique identifiers) according to RFC 4122.
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This module provides immutable UUID objects (class UUID) and the functions
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uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5
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UUIDs as specified in RFC 4122.
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If all you want is a unique ID, you should probably call uuid1() or uuid4().
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Note that uuid1() may compromise privacy since it creates a UUID containing
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the computer's network address. uuid4() creates a random UUID.
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Typical usage:
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>>> import uuid
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# make a UUID based on the host ID and current time
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>>> uuid.uuid1() # doctest: +SKIP
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UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
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# make a UUID using an MD5 hash of a namespace UUID and a name
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>>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
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UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
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# make a random UUID
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>>> uuid.uuid4() # doctest: +SKIP
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UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
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# make a UUID using a SHA-1 hash of a namespace UUID and a name
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>>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
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UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
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# make a UUID from a string of hex digits (braces and hyphens ignored)
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>>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')
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# convert a UUID to a string of hex digits in standard form
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>>> str(x)
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'00010203-0405-0607-0809-0a0b0c0d0e0f'
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# get the raw 16 bytes of the UUID
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>>> x.bytes
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b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'
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# make a UUID from a 16-byte string
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>>> uuid.UUID(bytes=x.bytes)
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UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
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"""
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import os
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import sys
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from enum import Enum
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__author__ = 'Ka-Ping Yee <ping@zesty.ca>'
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RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [
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'reserved for NCS compatibility', 'specified in RFC 4122',
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'reserved for Microsoft compatibility', 'reserved for future definition']
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int_ = int # The built-in int type
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bytes_ = bytes # The built-in bytes type
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class SafeUUID(Enum):
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safe = 0
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unsafe = -1
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unknown = None
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class UUID:
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"""Instances of the UUID class represent UUIDs as specified in RFC 4122.
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UUID objects are immutable, hashable, and usable as dictionary keys.
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Converting a UUID to a string with str() yields something in the form
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'12345678-1234-1234-1234-123456789abc'. The UUID constructor accepts
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five possible forms: a similar string of hexadecimal digits, or a tuple
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of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and
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48-bit values respectively) as an argument named 'fields', or a string
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of 16 bytes (with all the integer fields in big-endian order) as an
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argument named 'bytes', or a string of 16 bytes (with the first three
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fields in little-endian order) as an argument named 'bytes_le', or a
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single 128-bit integer as an argument named 'int'.
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UUIDs have these read-only attributes:
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bytes the UUID as a 16-byte string (containing the six
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integer fields in big-endian byte order)
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bytes_le the UUID as a 16-byte string (with time_low, time_mid,
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and time_hi_version in little-endian byte order)
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fields a tuple of the six integer fields of the UUID,
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which are also available as six individual attributes
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and two derived attributes:
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time_low the first 32 bits of the UUID
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time_mid the next 16 bits of the UUID
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time_hi_version the next 16 bits of the UUID
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clock_seq_hi_variant the next 8 bits of the UUID
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clock_seq_low the next 8 bits of the UUID
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node the last 48 bits of the UUID
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time the 60-bit timestamp
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clock_seq the 14-bit sequence number
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hex the UUID as a 32-character hexadecimal string
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int the UUID as a 128-bit integer
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urn the UUID as a URN as specified in RFC 4122
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variant the UUID variant (one of the constants RESERVED_NCS,
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RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE)
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version the UUID version number (1 through 5, meaningful only
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when the variant is RFC_4122)
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is_safe An enum indicating whether the UUID has been generated in
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a way that is safe for multiprocessing applications, via
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uuid_generate_time_safe(3).
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"""
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def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,
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int=None, version=None,
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*, is_safe=SafeUUID.unknown):
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r"""Create a UUID from either a string of 32 hexadecimal digits,
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a string of 16 bytes as the 'bytes' argument, a string of 16 bytes
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in little-endian order as the 'bytes_le' argument, a tuple of six
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integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,
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8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as
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the 'fields' argument, or a single 128-bit integer as the 'int'
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argument. When a string of hex digits is given, curly braces,
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hyphens, and a URN prefix are all optional. For example, these
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expressions all yield the same UUID:
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UUID('{12345678-1234-5678-1234-567812345678}')
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UUID('12345678123456781234567812345678')
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UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
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UUID(bytes='\x12\x34\x56\x78'*4)
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UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +
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'\x12\x34\x56\x78\x12\x34\x56\x78')
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UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
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UUID(int=0x12345678123456781234567812345678)
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Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must
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be given. The 'version' argument is optional; if given, the resulting
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UUID will have its variant and version set according to RFC 4122,
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overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'.
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is_safe is an enum exposed as an attribute on the instance. It
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indicates whether the UUID has been generated in a way that is safe
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for multiprocessing applications, via uuid_generate_time_safe(3).
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"""
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if [hex, bytes, bytes_le, fields, int].count(None) != 4:
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raise TypeError('one of the hex, bytes, bytes_le, fields, '
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'or int arguments must be given')
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if hex is not None:
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hex = hex.replace('urn:', '').replace('uuid:', '')
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hex = hex.strip('{}').replace('-', '')
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if len(hex) != 32:
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raise ValueError('badly formed hexadecimal UUID string')
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int = int_(hex, 16)
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if bytes_le is not None:
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if len(bytes_le) != 16:
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raise ValueError('bytes_le is not a 16-char string')
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bytes = (bytes_le[4-1::-1] + bytes_le[6-1:4-1:-1] +
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bytes_le[8-1:6-1:-1] + bytes_le[8:])
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if bytes is not None:
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if len(bytes) != 16:
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raise ValueError('bytes is not a 16-char string')
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assert isinstance(bytes, bytes_), repr(bytes)
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int = int_.from_bytes(bytes, byteorder='big')
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if fields is not None:
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if len(fields) != 6:
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raise ValueError('fields is not a 6-tuple')
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(time_low, time_mid, time_hi_version,
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clock_seq_hi_variant, clock_seq_low, node) = fields
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if not 0 <= time_low < 1<<32:
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raise ValueError('field 1 out of range (need a 32-bit value)')
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if not 0 <= time_mid < 1<<16:
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raise ValueError('field 2 out of range (need a 16-bit value)')
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if not 0 <= time_hi_version < 1<<16:
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raise ValueError('field 3 out of range (need a 16-bit value)')
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if not 0 <= clock_seq_hi_variant < 1<<8:
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raise ValueError('field 4 out of range (need an 8-bit value)')
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if not 0 <= clock_seq_low < 1<<8:
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raise ValueError('field 5 out of range (need an 8-bit value)')
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if not 0 <= node < 1<<48:
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raise ValueError('field 6 out of range (need a 48-bit value)')
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clock_seq = (clock_seq_hi_variant << 8) | clock_seq_low
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int = ((time_low << 96) | (time_mid << 80) |
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(time_hi_version << 64) | (clock_seq << 48) | node)
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if int is not None:
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if not 0 <= int < 1<<128:
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raise ValueError('int is out of range (need a 128-bit value)')
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if version is not None:
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if not 1 <= version <= 5:
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raise ValueError('illegal version number')
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# Set the variant to RFC 4122.
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int &= ~(0xc000 << 48)
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int |= 0x8000 << 48
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# Set the version number.
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int &= ~(0xf000 << 64)
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int |= version << 76
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self.__dict__['int'] = int
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self.__dict__['is_safe'] = is_safe
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def __getstate__(self):
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state = self.__dict__
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if self.is_safe != SafeUUID.unknown:
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# is_safe is a SafeUUID instance. Return just its value, so that
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# it can be un-pickled in older Python versions without SafeUUID.
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state = state.copy()
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state['is_safe'] = self.is_safe.value
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return state
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def __setstate__(self, state):
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self.__dict__.update(state)
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# is_safe was added in 3.7; it is also omitted when it is "unknown"
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self.__dict__['is_safe'] = (
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SafeUUID(state['is_safe'])
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if 'is_safe' in state else SafeUUID.unknown
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)
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def __eq__(self, other):
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if isinstance(other, UUID):
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return self.int == other.int
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return NotImplemented
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# Q. What's the value of being able to sort UUIDs?
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# A. Use them as keys in a B-Tree or similar mapping.
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def __lt__(self, other):
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if isinstance(other, UUID):
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return self.int < other.int
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return NotImplemented
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def __gt__(self, other):
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if isinstance(other, UUID):
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return self.int > other.int
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return NotImplemented
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def __le__(self, other):
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if isinstance(other, UUID):
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return self.int <= other.int
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return NotImplemented
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def __ge__(self, other):
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if isinstance(other, UUID):
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return self.int >= other.int
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return NotImplemented
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def __hash__(self):
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return hash(self.int)
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def __int__(self):
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return self.int
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def __repr__(self):
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return '%s(%r)' % (self.__class__.__name__, str(self))
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def __setattr__(self, name, value):
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raise TypeError('UUID objects are immutable')
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def __str__(self):
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hex = '%032x' % self.int
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return '%s-%s-%s-%s-%s' % (
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hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:])
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@property
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def bytes(self):
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return self.int.to_bytes(16, 'big')
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@property
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def bytes_le(self):
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bytes = self.bytes
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return (bytes[4-1::-1] + bytes[6-1:4-1:-1] + bytes[8-1:6-1:-1] +
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bytes[8:])
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@property
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def fields(self):
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return (self.time_low, self.time_mid, self.time_hi_version,
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self.clock_seq_hi_variant, self.clock_seq_low, self.node)
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@property
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def time_low(self):
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return self.int >> 96
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@property
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def time_mid(self):
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return (self.int >> 80) & 0xffff
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@property
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def time_hi_version(self):
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return (self.int >> 64) & 0xffff
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@property
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def clock_seq_hi_variant(self):
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return (self.int >> 56) & 0xff
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@property
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def clock_seq_low(self):
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return (self.int >> 48) & 0xff
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@property
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def time(self):
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return (((self.time_hi_version & 0x0fff) << 48) |
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(self.time_mid << 32) | self.time_low)
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@property
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def clock_seq(self):
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return (((self.clock_seq_hi_variant & 0x3f) << 8) |
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self.clock_seq_low)
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@property
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def node(self):
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return self.int & 0xffffffffffff
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@property
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def hex(self):
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return '%032x' % self.int
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@property
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def urn(self):
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return 'urn:uuid:' + str(self)
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@property
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def variant(self):
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if not self.int & (0x8000 << 48):
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return RESERVED_NCS
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elif not self.int & (0x4000 << 48):
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return RFC_4122
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elif not self.int & (0x2000 << 48):
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return RESERVED_MICROSOFT
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else:
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return RESERVED_FUTURE
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@property
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def version(self):
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# The version bits are only meaningful for RFC 4122 UUIDs.
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if self.variant == RFC_4122:
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return int((self.int >> 76) & 0xf)
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def _popen(command, *args):
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import os, shutil, subprocess
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executable = shutil.which(command)
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if executable is None:
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path = os.pathsep.join(('/sbin', '/usr/sbin'))
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executable = shutil.which(command, path=path)
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if executable is None:
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return None
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# LC_ALL=C to ensure English output, stderr=DEVNULL to prevent output
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# on stderr (Note: we don't have an example where the words we search
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# for are actually localized, but in theory some system could do so.)
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env = dict(os.environ)
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env['LC_ALL'] = 'C'
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proc = subprocess.Popen((executable,) + args,
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stdout=subprocess.PIPE,
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stderr=subprocess.DEVNULL,
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env=env)
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return proc
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# For MAC (a.k.a. IEEE 802, or EUI-48) addresses, the second least significant
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# bit of the first octet signifies whether the MAC address is universally (0)
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# or locally (1) administered. Network cards from hardware manufacturers will
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# always be universally administered to guarantee global uniqueness of the MAC
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# address, but any particular machine may have other interfaces which are
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# locally administered. An example of the latter is the bridge interface to
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# the Touch Bar on MacBook Pros.
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#
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# This bit works out to be the 42nd bit counting from 1 being the least
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# significant, or 1<<41. We'll prefer universally administered MAC addresses
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# over locally administered ones since the former are globally unique, but
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# we'll return the first of the latter found if that's all the machine has.
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#
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# See https://en.wikipedia.org/wiki/MAC_address#Universal_vs._local
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def _is_universal(mac):
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return not (mac & (1 << 41))
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def _find_mac(command, args, hw_identifiers, get_index):
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first_local_mac = None
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try:
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proc = _popen(command, *args.split())
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if not proc:
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return None
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with proc:
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for line in proc.stdout:
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words = line.lower().rstrip().split()
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for i in range(len(words)):
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if words[i] in hw_identifiers:
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try:
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word = words[get_index(i)]
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mac = int(word.replace(b':', b''), 16)
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if _is_universal(mac):
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return mac
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first_local_mac = first_local_mac or mac
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except (ValueError, IndexError):
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# Virtual interfaces, such as those provided by
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# VPNs, do not have a colon-delimited MAC address
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# as expected, but a 16-byte HWAddr separated by
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# dashes. These should be ignored in favor of a
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# real MAC address
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pass
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except OSError:
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pass
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return first_local_mac or None
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def _ifconfig_getnode():
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"""Get the hardware address on Unix by running ifconfig."""
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# This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes.
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keywords = (b'hwaddr', b'ether', b'address:', b'lladdr')
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for args in ('', '-a', '-av'):
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mac = _find_mac('ifconfig', args, keywords, lambda i: i+1)
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if mac:
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return mac
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return None
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def _ip_getnode():
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"""Get the hardware address on Unix by running ip."""
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# This works on Linux with iproute2.
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mac = _find_mac('ip', 'link', [b'link/ether'], lambda i: i+1)
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if mac:
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return mac
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return None
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def _arp_getnode():
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"""Get the hardware address on Unix by running arp."""
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import os, socket
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try:
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ip_addr = socket.gethostbyname(socket.gethostname())
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except OSError:
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return None
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# Try getting the MAC addr from arp based on our IP address (Solaris).
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mac = _find_mac('arp', '-an', [os.fsencode(ip_addr)], lambda i: -1)
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if mac:
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return mac
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# This works on OpenBSD
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mac = _find_mac('arp', '-an', [os.fsencode(ip_addr)], lambda i: i+1)
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if mac:
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return mac
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# This works on Linux, FreeBSD and NetBSD
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mac = _find_mac('arp', '-an', [os.fsencode('(%s)' % ip_addr)],
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lambda i: i+2)
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# Return None instead of 0.
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if mac:
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return mac
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return None
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def _lanscan_getnode():
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"""Get the hardware address on Unix by running lanscan."""
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# This might work on HP-UX.
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return _find_mac('lanscan', '-ai', [b'lan0'], lambda i: 0)
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def _netstat_getnode():
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"""Get the hardware address on Unix by running netstat."""
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# This might work on AIX, Tru64 UNIX.
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first_local_mac = None
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try:
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proc = _popen('netstat', '-ia')
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if not proc:
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return None
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with proc:
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words = proc.stdout.readline().rstrip().split()
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try:
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i = words.index(b'Address')
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except ValueError:
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return None
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for line in proc.stdout:
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try:
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words = line.rstrip().split()
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word = words[i]
|
|
if len(word) == 17 and word.count(b':') == 5:
|
|
mac = int(word.replace(b':', b''), 16)
|
|
if _is_universal(mac):
|
|
return mac
|
|
first_local_mac = first_local_mac or mac
|
|
except (ValueError, IndexError):
|
|
pass
|
|
except OSError:
|
|
pass
|
|
return first_local_mac or None
|
|
|
|
def _ipconfig_getnode():
|
|
"""Get the hardware address on Windows by running ipconfig.exe."""
|
|
import os, re, subprocess
|
|
first_local_mac = None
|
|
dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']
|
|
try:
|
|
import ctypes
|
|
buffer = ctypes.create_string_buffer(300)
|
|
ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300)
|
|
dirs.insert(0, buffer.value.decode('mbcs'))
|
|
except:
|
|
pass
|
|
for dir in dirs:
|
|
try:
|
|
proc = subprocess.Popen([os.path.join(dir, 'ipconfig'), '/all'],
|
|
stdout=subprocess.PIPE,
|
|
encoding="oem")
|
|
except OSError:
|
|
continue
|
|
with proc:
|
|
for line in proc.stdout:
|
|
value = line.split(':')[-1].strip().lower()
|
|
if re.fullmatch('(?:[0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):
|
|
mac = int(value.replace('-', ''), 16)
|
|
if _is_universal(mac):
|
|
return mac
|
|
first_local_mac = first_local_mac or mac
|
|
return first_local_mac or None
|
|
|
|
def _netbios_getnode():
|
|
"""Get the hardware address on Windows using NetBIOS calls.
|
|
See http://support.microsoft.com/kb/118623 for details."""
|
|
import win32wnet, netbios
|
|
first_local_mac = None
|
|
ncb = netbios.NCB()
|
|
ncb.Command = netbios.NCBENUM
|
|
ncb.Buffer = adapters = netbios.LANA_ENUM()
|
|
adapters._pack()
|
|
if win32wnet.Netbios(ncb) != 0:
|
|
return None
|
|
adapters._unpack()
|
|
for i in range(adapters.length):
|
|
ncb.Reset()
|
|
ncb.Command = netbios.NCBRESET
|
|
ncb.Lana_num = ord(adapters.lana[i])
|
|
if win32wnet.Netbios(ncb) != 0:
|
|
continue
|
|
ncb.Reset()
|
|
ncb.Command = netbios.NCBASTAT
|
|
ncb.Lana_num = ord(adapters.lana[i])
|
|
ncb.Callname = '*'.ljust(16)
|
|
ncb.Buffer = status = netbios.ADAPTER_STATUS()
|
|
if win32wnet.Netbios(ncb) != 0:
|
|
continue
|
|
status._unpack()
|
|
bytes = status.adapter_address[:6]
|
|
if len(bytes) != 6:
|
|
continue
|
|
mac = int.from_bytes(bytes, 'big')
|
|
if _is_universal(mac):
|
|
return mac
|
|
first_local_mac = first_local_mac or mac
|
|
return first_local_mac or None
|
|
|
|
|
|
_generate_time_safe = _UuidCreate = None
|
|
_has_uuid_generate_time_safe = None
|
|
|
|
# Import optional C extension at toplevel, to help disabling it when testing
|
|
try:
|
|
import _uuid
|
|
except ImportError:
|
|
_uuid = None
|
|
|
|
|
|
def _load_system_functions():
|
|
"""
|
|
Try to load platform-specific functions for generating uuids.
|
|
"""
|
|
global _generate_time_safe, _UuidCreate, _has_uuid_generate_time_safe
|
|
|
|
if _has_uuid_generate_time_safe is not None:
|
|
return
|
|
|
|
_has_uuid_generate_time_safe = False
|
|
|
|
if sys.platform == "darwin" and int(os.uname().release.split('.')[0]) < 9:
|
|
# The uuid_generate_* functions are broken on MacOS X 10.5, as noted
|
|
# in issue #8621 the function generates the same sequence of values
|
|
# in the parent process and all children created using fork (unless
|
|
# those children use exec as well).
|
|
#
|
|
# Assume that the uuid_generate functions are broken from 10.5 onward,
|
|
# the test can be adjusted when a later version is fixed.
|
|
pass
|
|
elif _uuid is not None:
|
|
_generate_time_safe = _uuid.generate_time_safe
|
|
_has_uuid_generate_time_safe = _uuid.has_uuid_generate_time_safe
|
|
return
|
|
|
|
try:
|
|
# If we couldn't find an extension module, try ctypes to find
|
|
# system routines for UUID generation.
|
|
# Thanks to Thomas Heller for ctypes and for his help with its use here.
|
|
import ctypes
|
|
import ctypes.util
|
|
|
|
# The uuid_generate_* routines are provided by libuuid on at least
|
|
# Linux and FreeBSD, and provided by libc on Mac OS X.
|
|
_libnames = ['uuid']
|
|
if not sys.platform.startswith('win'):
|
|
_libnames.append('c')
|
|
for libname in _libnames:
|
|
try:
|
|
lib = ctypes.CDLL(ctypes.util.find_library(libname))
|
|
except Exception: # pragma: nocover
|
|
continue
|
|
# Try to find the safe variety first.
|
|
if hasattr(lib, 'uuid_generate_time_safe'):
|
|
_uuid_generate_time_safe = lib.uuid_generate_time_safe
|
|
# int uuid_generate_time_safe(uuid_t out);
|
|
def _generate_time_safe():
|
|
_buffer = ctypes.create_string_buffer(16)
|
|
res = _uuid_generate_time_safe(_buffer)
|
|
return bytes(_buffer.raw), res
|
|
_has_uuid_generate_time_safe = True
|
|
break
|
|
|
|
elif hasattr(lib, 'uuid_generate_time'): # pragma: nocover
|
|
_uuid_generate_time = lib.uuid_generate_time
|
|
# void uuid_generate_time(uuid_t out);
|
|
_uuid_generate_time.restype = None
|
|
def _generate_time_safe():
|
|
_buffer = ctypes.create_string_buffer(16)
|
|
_uuid_generate_time(_buffer)
|
|
return bytes(_buffer.raw), None
|
|
break
|
|
|
|
# On Windows prior to 2000, UuidCreate gives a UUID containing the
|
|
# hardware address. On Windows 2000 and later, UuidCreate makes a
|
|
# random UUID and UuidCreateSequential gives a UUID containing the
|
|
# hardware address. These routines are provided by the RPC runtime.
|
|
# NOTE: at least on Tim's WinXP Pro SP2 desktop box, while the last
|
|
# 6 bytes returned by UuidCreateSequential are fixed, they don't appear
|
|
# to bear any relationship to the MAC address of any network device
|
|
# on the box.
|
|
try:
|
|
lib = ctypes.windll.rpcrt4
|
|
except:
|
|
lib = None
|
|
_UuidCreate = getattr(lib, 'UuidCreateSequential',
|
|
getattr(lib, 'UuidCreate', None))
|
|
|
|
except Exception as exc:
|
|
import warnings
|
|
warnings.warn(f"Could not find fallback ctypes uuid functions: {exc}",
|
|
ImportWarning)
|
|
|
|
|
|
def _unix_getnode():
|
|
"""Get the hardware address on Unix using the _uuid extension module
|
|
or ctypes."""
|
|
_load_system_functions()
|
|
uuid_time, _ = _generate_time_safe()
|
|
return UUID(bytes=uuid_time).node
|
|
|
|
def _windll_getnode():
|
|
"""Get the hardware address on Windows using ctypes."""
|
|
import ctypes
|
|
_load_system_functions()
|
|
_buffer = ctypes.create_string_buffer(16)
|
|
if _UuidCreate(_buffer) == 0:
|
|
return UUID(bytes=bytes_(_buffer.raw)).node
|
|
|
|
def _random_getnode():
|
|
"""Get a random node ID."""
|
|
# RFC 4122, $4.1.6 says "For systems with no IEEE address, a randomly or
|
|
# pseudo-randomly generated value may be used; see Section 4.5. The
|
|
# multicast bit must be set in such addresses, in order that they will
|
|
# never conflict with addresses obtained from network cards."
|
|
#
|
|
# The "multicast bit" of a MAC address is defined to be "the least
|
|
# significant bit of the first octet". This works out to be the 41st bit
|
|
# counting from 1 being the least significant bit, or 1<<40.
|
|
#
|
|
# See https://en.wikipedia.org/wiki/MAC_address#Unicast_vs._multicast
|
|
import random
|
|
return random.getrandbits(48) | (1 << 40)
|
|
|
|
|
|
_node = None
|
|
|
|
_NODE_GETTERS_WIN32 = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
|
|
|
|
_NODE_GETTERS_UNIX = [_unix_getnode, _ifconfig_getnode, _ip_getnode,
|
|
_arp_getnode, _lanscan_getnode, _netstat_getnode]
|
|
|
|
def getnode(*, getters=None):
|
|
"""Get the hardware address as a 48-bit positive integer.
|
|
|
|
The first time this runs, it may launch a separate program, which could
|
|
be quite slow. If all attempts to obtain the hardware address fail, we
|
|
choose a random 48-bit number with its eighth bit set to 1 as recommended
|
|
in RFC 4122.
|
|
"""
|
|
global _node
|
|
if _node is not None:
|
|
return _node
|
|
|
|
if sys.platform == 'win32':
|
|
getters = _NODE_GETTERS_WIN32
|
|
else:
|
|
getters = _NODE_GETTERS_UNIX
|
|
|
|
for getter in getters + [_random_getnode]:
|
|
try:
|
|
_node = getter()
|
|
except:
|
|
continue
|
|
if (_node is not None) and (0 <= _node < (1 << 48)):
|
|
return _node
|
|
assert False, '_random_getnode() returned invalid value: {}'.format(_node)
|
|
|
|
|
|
_last_timestamp = None
|
|
|
|
def uuid1(node=None, clock_seq=None):
|
|
"""Generate a UUID from a host ID, sequence number, and the current time.
|
|
If 'node' is not given, getnode() is used to obtain the hardware
|
|
address. If 'clock_seq' is given, it is used as the sequence number;
|
|
otherwise a random 14-bit sequence number is chosen."""
|
|
|
|
# When the system provides a version-1 UUID generator, use it (but don't
|
|
# use UuidCreate here because its UUIDs don't conform to RFC 4122).
|
|
_load_system_functions()
|
|
if _generate_time_safe is not None and node is clock_seq is None:
|
|
uuid_time, safely_generated = _generate_time_safe()
|
|
try:
|
|
is_safe = SafeUUID(safely_generated)
|
|
except ValueError:
|
|
is_safe = SafeUUID.unknown
|
|
return UUID(bytes=uuid_time, is_safe=is_safe)
|
|
|
|
global _last_timestamp
|
|
import time
|
|
nanoseconds = int(time.time() * 1e9)
|
|
# 0x01b21dd213814000 is the number of 100-ns intervals between the
|
|
# UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.
|
|
timestamp = int(nanoseconds/100) + 0x01b21dd213814000
|
|
if _last_timestamp is not None and timestamp <= _last_timestamp:
|
|
timestamp = _last_timestamp + 1
|
|
_last_timestamp = timestamp
|
|
if clock_seq is None:
|
|
import random
|
|
clock_seq = random.getrandbits(14) # instead of stable storage
|
|
time_low = timestamp & 0xffffffff
|
|
time_mid = (timestamp >> 32) & 0xffff
|
|
time_hi_version = (timestamp >> 48) & 0x0fff
|
|
clock_seq_low = clock_seq & 0xff
|
|
clock_seq_hi_variant = (clock_seq >> 8) & 0x3f
|
|
if node is None:
|
|
node = getnode()
|
|
return UUID(fields=(time_low, time_mid, time_hi_version,
|
|
clock_seq_hi_variant, clock_seq_low, node), version=1)
|
|
|
|
def uuid3(namespace, name):
|
|
"""Generate a UUID from the MD5 hash of a namespace UUID and a name."""
|
|
from hashlib import md5
|
|
hash = md5(namespace.bytes + bytes(name, "utf-8")).digest()
|
|
return UUID(bytes=hash[:16], version=3)
|
|
|
|
def uuid4():
|
|
"""Generate a random UUID."""
|
|
return UUID(bytes=os.urandom(16), version=4)
|
|
|
|
def uuid5(namespace, name):
|
|
"""Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""
|
|
from hashlib import sha1
|
|
hash = sha1(namespace.bytes + bytes(name, "utf-8")).digest()
|
|
return UUID(bytes=hash[:16], version=5)
|
|
|
|
# The following standard UUIDs are for use with uuid3() or uuid5().
|
|
|
|
NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8')
|