def get_trx_groups(data, group_key='_ifft_0'):
    lst = data.columns[data.columns.str.contains(group_key)]
    groups = [[x[:(- 2)]] for x in lst]
    return groups
def get_trx_groups(data, group_key='_ifft_0'):
    lst = data.columns[data.columns.str.contains(group_key)]
    groups = [[x[:(- 2)]] for x in lst]
    return groups