问题描述:
Write a function to get the angle of a complex number.

测试用例:
['assert angle_complex(0,1j)==1.5707963267948966 ', 'assert angle_complex(2,1j)==0.4636476090008061', 'assert angle_complex(0,2j)==1.5707963267948966']

生成的代码:
import cmath

def angle_complex(real, imag):
    return cmath.phase(complex(real, imag))