Negative exponential fitting in Phyton

I need to do a negative exponential fitting [y= Ae^(-x/B)+C] for different curves, which are described as follows:

X=[1,2,3,4,5,6,7,8,9,10]

Y1= [1.0, 0.44495152287550843, 0.3779760039039391, 0.34115384290246453, 0.3240391485208877, 0.3076827423802232, 0.3000907282591817, 0.29134998822820984, 0.28467099215488817, 0.2761381428114057]
Y2= [1.0, 0.5169751061131599, 0.4496628708209092, 0.41752144157724197, 0.40007094615859057, 0.3857003042574854, 0.3736941871136991, 0.36564774508240105, 0.362514593995446, 0.354684877403943]
Y3= [1.0, 0.48068378880616963, 0.41545983973891004, 0.3841003409265993, 0.36105104680772443, 0.3460520526483223, 0.3422856368032703, 0.32968538016277277, 0.32595626290689633, 0.3208378788541345]
Y4= [1.0, 0.46947897026845997, 0.4022375965045462, 0.37259136270017473, 0.34921151209089446, 0.335390144007578, 0.3234647790341758, 0.3149546896928853, 0.3095751479742552, 0.3022819088522179]

I am looking for the code, but I am not able to find the right one for more than one curve.