How do you express binary literals in Python?

Question

How do you express an integer as a binary number with Python literals?

I was easily able to find the answer for hex:

>>> 0x12AF 4783 >>> 0x100 256 

and octal:

>>> 01267 695 >>> 0100 64 

How do you use literals to express binary in Python?

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Summary of Answers

• Python 2.5 and earlier: can express binary using int('01010101111',2) but not with a literal.
• Python 2.5 and earlier: there is no way to express binary literals.
• Python 2.6 beta: You can do like so: 0b1100111 or 0B1100111.
• Python 2.6 beta: will also allow 0o27 or 0O27 (second character is the letter O) to represent an octal.
• Python 3.0 beta: Same as 2.6, but will no longer allow the older 027 syntax for octals.

Answer 1

For reference—future Python possibilities:
Starting with Python 2.6 you can express binary literals using the prefix 0b or 0B:

>>> 0b101111 47 

You can also use the new bin function to get the binary representation of a number:

>>> bin(173) '0b10101101' 

Development version of the documentation: What's New in Python 2.6

Answer 2

>>> print int('01010101111',2) 687 >>> print int('11111111',2) 255 

Another way.