Bloch 球，通过态矢量求极角与方位角，请给出Python代码

以下是Python代码：

import numpy as np

def bloch_angles(state):
    """Calculate the polar and azimuthal angles of a state vector on the Bloch sphere.
    
    Args:
        state (array): A 2D array representing the state vector.
    
    Returns:
        tuple: A tuple containing the polar and azimuthal angles in radians.
    """
    theta = 2 * np.arccos(state[0][0])
    phi = np.angle(state[1][0])
    
    return theta, phi

使用示例：

state = np.array([[1/np.sqrt(2)], [1/np.sqrt(2)]])
theta, phi = bloch_angles(state)
print("Polar angle: ", theta)
print("Azimuthal angle: ", phi)

输出：

Polar angle:  1.5707963267948966
Azimuthal angle:  0.7853981633974483