regex.sub() gives different results to re.sub()

Question

I work with Czech accented text in Python 3.4.

Calling re.sub() to perform substitution by regex on an accented sentence works well, but using a regex compiled with

Answer 1

The last argument in the compile is flags, if you actually use flags=flags in the re.sub you will see the same behaviour:

compiled = re.compile(pattern, flags)
print(compiled)
text = 'Poplatníkem daně z pozemků je vlastník pozemku'
mark = r'**\1**' # wrap 1st matching group in double stars

r = re.sub(pattern, mark, text, flags=flags)

The fourth arg to re.sub is count so that is why you see the difference.

re.sub(pattern, repl, string, count=0, flags=0)

re.compile(pattern, flags=0)