filepath = "C:/abc5/Python/Clustering/output2.csv"
df = pd.read_csv(filepath,encoding='windows-1252')

df["newlist"] = df["text_lemmatized"]
for i in range(0,len(df)):
    l = df["text_lemmatized"][i]
    df["newlist"][i] = list(dict.fromkeys(l))

print(df)

['clear', 'pending', 'order', 'pending', 'order']   ['clear', 'pending', 'order']
 ['pending', 'activation', 'clear', 'pending']   ['pending', 'activation', 'clear']

['clear', 'pending', 'order', 'pending', 'order']  ...   [[, ', c, l, e, a, r, ,,  , p, n, d, i, g, o, ]]
['pending', 'activation', 'clear', 'pending', ...  ...  [[, ', p, e, n, d, i, g, ,,  , a, c, t, v, o, ...