short code not working for unknown reason

θ diedro,ΔE(Eₒ−Z.P.E),,,θ diedro,ΔE(Eₒ−Z.P.E),,,θ diedro,ΔE(Eₒ−Z.P.E),,,θ diedro,ΔE(Eₒ−Z.P.E)
"0,0000","-0,0006",,,"0,0000","0,0006",,,"0,0000","0,0025",,,"0,0000","-0,0013"
"20,0000","0,5183",,,"20,0000","0,5459",,,"20,0000","0,6194",,,"20,0000","0,5190"
"40,0000","1,8549",,,"40,0000","1,9271",,,"40,0000","1,9905",,,"40,0000","1,7972"
"60,0000","2,8878",,,"60,0000","2,9474",,,"60,0000","2,8734",,,"60,0000","2,6807"
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.
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import pandas as pd
import matplotlib.pyplot as plt

filename='valen.csv'

data1 = pd.read_csv(filename,usecols=[0,1], nrows=20, decimal=',')
#data2 = pd.read_csv(filename,usecols=[4,5], nrows=20,decimal=',')
#data3 = pd.read_csv(filename,usecols=[8,9], nrows=20,decimal=',')

y=data1.iloc[:,1]
x=data1.iloc[:,0]

plt.plot(x,y)

plt.show()


#problem: it returns an error: UnicodeDecodeError: 'ascii' codec can't decode byte 0xce in position 0: ordinal not in range(128)