Python offset bug

offset_bug.py

#!/usr/bin/env python3
#-*- coding:utf-8 -*-

SYNTAXERROR_TEMPLATE = "%s = ())" # Unbalanced parentheses

def get_offset(varname):
    """Trigger a syntax error that uses the given variable name and return the
    exception's offset, e.g. the position of the syntax error.
    
    """
    try:
        exec(SYNTAXERROR_TEMPLATE % varname)
    except SyntaxError as e:
        return e.offset

def get_expected_offset(varname):
    return len(SYNTAXERROR_TEMPLATE % varname) # The error is on the last paren

# Three identifiers of length 1 that use 1, 2 and 3 bytes respectively
VARNAMES = ['a', 'é', '蟒']

for v in VARNAMES:
    print("Expected: %s, Got: %s" % (get_expected_offset(v), get_offset(v)))