I did not change the original data set value, i just follow the standard answer to do my project, but all my ranking columns are either 0 or NAN. why?
Thank you.
Screen Link: https://app.dataquest.io/m/201/guided-project%3A-star-wars-survey/5/cleaning-the-ranking-columns
My Code:
#Rename the ranking columns
star_wars.rename(columns={
"Please rank the Star Wars films in order of preference with 1 being your favorite film in the franchise and 6 being your least favorite film.": "ranking_1",
"Unnamed: 10": "ranking_2",
"Unnamed: 11": "ranking_3",
"Unnamed: 12": "ranking_4",
"Unnamed: 13": "ranking_5",
"Unnamed: 14": "ranking_6"
},inplace=True)
#change ranking to numeric
star_wars[star_wars.columns[9:15]] = star_wars[star_wars.columns[9:15]].astype(float)
star_wars['ranking_2'].value_counts(dropna=False)