a = df['column name'].unique() #returns a list of unique values
df.groupby('param')['column'].nunique().sort_values(ascending=False).unique().tolist()
mylist = ['nowplaying', 'PBS', 'PBS', 'nowplaying', 'job', 'debate', 'thenandnow']
myset = set(mylist)
print(myset)
mynewlist = list(myset)
#['nowplaying', 'PBS', 'job', 'debate', 'thenandnow']
# just turn it into a set and then convert again into a list
res = list(set(lst1)))
# now check the lengths of the two lists
print(len(res))
print(len(lst1))