Implement `String.eight_bit_signed_number?` (Ruby), `String.eightBitSignedNumber()` (Python), `eight_bit_signed_number()` (JS) or `StringUtils.isSignedEightBitNumber(String)` (Java) which should return `true/True` if given object is a number representable by 8 bit signed integer (-128 to -1 or 0 to 127), `false/False` otherwise.
It should only accept numbers in canonical representation, so no leading `+`, extra `0`s, spaces etc.
import re
def signed_eight_bit_number(n):
    return re.match(r'-?\d+$',n)and str(int(n))==n and -128<=int(n)<128 or False
import re
def signed_eight_bit_number(n):
    return re.match(r'-?\d+$',n)and str(int(n))==n and -128<=int(n)<128 or False