def arc_tangent(value):
    'Filter to get arc tangent of the value.'
    try:
        return math.atan(float(value))
    except (ValueError, TypeError):
        return value
Filter to get arc tangent of the value.
def arc_tangent(value):
    
    try:
        return math.atan(float(value))
    except (ValueError, TypeError):
        return value