Answers for "get number of unique values"

return count of unique values pandas

#TO count repetition of each unique values(to find How many times the same-
# unique value is appearing in the data)

item_counts = df["Your_Column"].value_counts()
#Returns Dictionary => {"Value_name" : number_of_appearences}

Return a Series containing counts of unique values.

print(df["os"].value_counts())