band-pass filtering

from scipy import signal
# 带通滤波器
# 信号，频率下限，频率上限， 采样率
def bandPass(signals, fre_low, fre_high, fs):
    b, a = signal.butter(8, [2.0 * fre_low / fs, 2.0 * fre_high / fs], 'bandpass', 'sos')
    filtedData = signal.filtfilt(b, a, signals)
    return filtedData