In Python 2, integer literals with leading zeroes are treated as octal, so 09 is a syntax error and 010 is 8.
This is confusing to those not raised on C-style octal literals, so in Python 3 leading zeroes are prohibited in int literals. Octal is instead written using the prefix 0o, similar to hex 0x and binary 0b. Consequently Python 3 makes both 09 and 010 a syntax error. However there is one exception: zero itself is allowed any number of leading zeroes, so 00000 is a legal way to write zero as a base-10 int literal. Does anyone use that (mis)feature? -- Steven -- https://mail.python.org/mailman/listinfo/python-list
