python - Why the below piece of regular expression code is returning comma(,) -

please let me know why following piece of code giving below result

>>> pattern = re.compile(r'[!#$%&()*+-.]') >>> pattern.findall("a,b") [','] 

there no comma(,) symbol in re.compile method, why matching comma also?

[+-.] single character in range + (ascii 43) . (ascii 46).

between 2 characters find , (ascii 44) , - (ascii 45).

i guess wanted \- instead of -.