from hashlib import sha256
 
digits58 = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
 
def decode_base58(bc, length):
    n = 0
    for char in bc:
        n = n * 58 + digits58.index(char)
    return n.to_bytes(length, 'big')
def check_bc(bc):
    try:
        bcbytes = decode_base58(bc, 25)
        return bcbytes[-4:] == sha256(sha256(bcbytes[:-4]).digest()).digest()[:4]
    except Exception:`
        return False
 
print(check_bc('FN93RGsz25vUPMwoyzQvrM95G5M42PGNWS'))