Python 2.X users can code octals with simply a leading zero, the original octal format in Python:
print( 0o1, 0o20, 0o377 ) # New octal format in 2.6+ (same as 3.X) #print( 01, 020, 0377 ) # Old octal literals in all 2.X (error in 3.X)
In 3.X, the syntax generates an error.
Python 2.X will treat a string of digits with a leading zero as base 8.
010 is always decimal 8 in 2.X, not decimal 10.
In 3.X you must use 0o010 to present octals.