Python 2.7 str(055) returns "45" instead of 055 [duplicate]

Question

Why I get the following result in python 2.7, instead of '055'?

>>> str(055)
'45'

Answer 1

055 is an octal number whose decimal equivalent is 45, use oct to get the correct output.

>>> oct(055)
'055'

Syntax for octal numbers in Python 2.X:

octinteger     ::=  "0" ("o" | "O") octdigit+ | "0" octdigit+

But this is just for representation purpose, ultimately they are always converted to integers for either storing or calculation:

>>> x = 055
>>> x
45
>>> x = 0xff   # HexaDecimal
>>> x
255
>>> x = 0b111  # Binary
>>> x
7
>>> 0xff * 055
11475

Note that in Python 3.x octal numbers are now represented by 0o. So, using 055 there will raise SyntaxError.