list comprehension
A compact way to process all or part of the elements in a sequence and
- return a list with the results. ``result = ["0x%02x" % x for x in
+ return a list with the results. ``result = ['{:#04x}'.format(x) for x in
range(256) if x % 2 == 0]`` generates a list of strings containing
even hex numbers (0x..) in the range from 0 to 255. The :keyword:`if`
clause is optional. If omitted, all elements in ``range(256)`` are
object drops to zero, it is deallocated. Reference counting is
generally not visible to Python code, but it is a key element of the
:term:`CPython` implementation. The :mod:`sys` module defines a
- :func:`getrefcount` function that programmers can call to return the
+ :func:`~sys.getrefcount` function that programmers can call to return the
reference count for a particular object.
__slots__
use as a checksum algorithm, it is not suitable for use as a general hash
algorithm. Use as follows::
- print(binascii.crc32("hello world"))
+ print(binascii.crc32(b"hello world"))
# Or, in two pieces:
- crc = binascii.crc32("hello")
- crc = binascii.crc32(" world", crc) & 0xffffffff
- print('crc32 = 0x%08x' % crc)
+ crc = binascii.crc32(b"hello")
+ crc = binascii.crc32(b" world", crc) & 0xffffffff
+ print('crc32 = {:#010x}'.format(crc))
.. note::
To generate the same numeric value across all Python versions and