cmath.py 文件源码

def rect(r, phi):
    _rect_special = [
        [inf+nanj, None, -inf, complex(-float("inf"), -0.0), None, inf+nanj, inf+nanj],
        [nan+nanj, None, None, None, None, nan+nanj, nan+nanj],
        [0, None, complex(-0.0, 0.0), complex(-0.0, -0.0), None, 0, 0],
        [0, None, complex(0.0, -0.0), 0, None, 0, 0],
        [nan+nanj, None, None, None, None, nan+nanj, nan+nanj],
        [inf+nanj, None, complex(float("inf"), -0.0), inf, None, inf+nanj, inf+nanj],
        [nan+nanj, nan+nanj, nan, nan, nan+nanj, nan+nanj, nan+nanj]
    ]

    if not math.isfinite(r) or not math.isfinite(phi):
        if math.isinf(phi) and not math.isnan(r) and r != 0:
            raise ValueError
        if math.isinf(r) and math.isfinite(phi) and phi != 0:
            if r > 0:
                return complex(math.copysign(inf, math.cos(phi)),
                               math.copysign(inf, math.sin(phi)))
            return complex(-math.copysign(inf, math.cos(phi)),
                           -math.copysign(inf, math.sin(phi)))
        return _rect_special[_special_type(r)][_special_type(phi)]
    return complex(r*math.cos(phi), r*math.sin(phi))