import unicodedata

width_mapping = {'F':2, 'H': 1, 'W': 2, 'Na': 1, 'N': 1}
def width(s):
    result = 0
    for c in s:
        w = unicodedata.east_asian_width(c)
        if c == 'A':
            # ambiguous
            raise ValueError("ambiguous character %x" % (ord(c)))
        result += width_mapping[w]
    return result

print(width("foo"))
print(width("整數"))