(s1, s2)
return "".join(map(lambda x,y:chr(ord(x)&ord(y)), s1, s2))
Returns the binary AND of the 2 provided strings s1 and s2. s1 and s2
    must be of same length.
Returns the binary AND of the 2 provided strings s1 and s2. s1 and s2
    must be of same length.
Returns the binary AND of the 2 provided strings s1 and s2 . s1 and s2 must be of same length .
def strand(s1, s2):
    """
    Returns the binary AND of the 2 provided strings s1 and s2. s1 and s2
    must be of same length.
    """
    return "".join(map(lambda x,y:chr(ord(x)&ord(y)), s1, s2))
def strand ( s1 , s2 ) : return "" . join ( map ( lambda x , y : chr ( ord ( x ) & ord ( y ) ) , s1 , s2 ) )