python dict reverse fourier code example

Example 1: fast fourier transform python

# This is from the question
from scipy.fftpack import fft

# Number of samplepoints
N = 600

# Sample spacing
T = 1.0 / 800.0
x = np.linspace(0.0, N*T, N)
y = np.sin(50.0 * 2.0*np.pi*x) + 0.5*np.sin(80.0 * 2.0*np.pi*x)
yf = fft(y)

Example 2: how to reverse a dictionary in python

def inverse_dict(my_dict):
    """
    the func get a dictinary and reverse it, the keys become values and the values become keys.
    :param my_dict: the dictinary that need to be reversed.
    :return: a VERY pretty dictionary.
    """
    result_dict = {}
    for key, value in my_dict.items():
        if not value in result_dict.keys():
            result_dict[value] = []
        result_dict[value].append(key)
    return result_dict, print(result_dict)