Can't assign custom indicator output to lines

[omryzci]

Hi, I need to backtest my custom indicator.

It returns two lines upper and lower bands.
types are numpy array.

def custom_ind(close,length,some parameterssss):
    close=np.array(close)
    y=[]
    sum_e=0.0
    e=2.718281
#Some code blocks here calculates upband,downband#
return upband,downband

I want to assign those upband and downband arrays into self.l.up and self.l.down

class custom_indicator(bt.Indicator):

    lines = ('upper','lower')
    params = (('period', 100),)
    def __init__(self):
        [upband,downband] = custon_ind(self.data,100,3,2)
        self.l.upper=upper

The error I go is as follows:

can you please help me with that:

TypeError: 'numpy.ndarray' object is not callable

[omryzci]

@omryzci

correction

self.l.upper=upband

error raises here