Bitwise NOT Operator for Sage?

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The bitwise not in Python is supposed to be ~(see https://wiki.python.org/moin/BitwiseO... about how negative numbers are encoded), but Sage's preparser first transforms 0b1000 as an element of ZZ for which the action of ~ is the multiplicative inverse:

sage: ~0b1000
1/8

This is because, in Sage:

sage: 0b1000.parent()
Integer Ring
sage: preparse("0b1000")
"Integer('1000', 2)"

To get the python behaviour, you can either turn the sage preparser off:

sage: preparser(False)
sage: ~0b1000
-9

or explicitely use python int:

sage: ~int(0b1000)
-9

Another workaround is to notice that not a is the same as a xor 1.