0o205

0o205 is a numeric representation in octal notation, a base-8 numeral system. The prefix 0o indicates that the digits that follow are to be interpreted as octal digits (0 through 7).

In octal, the value 0o205 equals 2×8^2 + 0×8^1 + 5×8^0, which is 133 in decimal. This value corresponds to 0x85 in hexadecimal. Octal notation is commonly used in various computing contexts to represent permissions, byte values, and other low-level data, where the grouping of bits into octal digits can be convenient.

In programming languages, 0o205 is a literal that explicitly denotes an octal number. Python 3 uses the 0o prefix for octal literals to distinguish them from decimal and hexadecimal literals. By comparison, earlier Python versions used a leading zero (for example 025) to indicate octal, but this could lead to confusion with decimal numbers that have leading zeros. Other languages, such as some shells and configuration formats, may support octal values with similar concepts, though the exact syntax can vary.

Notable properties include that 0o205 is a valid octal literal only because the digits 2, 0, and 5 are all in the 0–7 range. If any digit were 8 or 9, the notation would be invalid in octal. Octal representations are sometimes used in computing to express bit patterns or file permissions in a compact form.

See also: octal numeral system, numeric literals, Python (programming language).