Comparing Ratings by Gender and Plotting Them

import pandas as pd
import matplotlib.pyplot as plt
def movie(nogui=False, movielenspath=''):
    user_columns = ['user_id', 'age', 'gender']
    users = pd.read_csv(movielenspath + 'movie_lens/u.user', sep='|', names=user_columns, usecols=range(3))
    rating_columns = ['user_id', 'movie_id', 'rating']
    ratings = pd.read_csv(movielenspath + 'movie_lens/u.data', sep='\t', names=rating_columns,  usecols=range(3))
    movie_columns = ['movie_id', 'title']
    movies = pd.read_csv(movielenspath + 'movie_lens/u.item', sep='|', names=movie_columns, usecols=range(2), encoding="iso-8859-1")
    # create one merged DataFrame
    movie_ratings = pd.merge(movies, ratings)
    movie_data = pd.merge(movie_ratings, users)
    
    ratings_by_title = movie_data.groupby('title').size()
    popular_movies = ratings_by_title.index[ratings_by_title >= 250]
    ratings_by_gender = movie_data.pivot_table('rating', index='title',columns='gender')
    ratings_by_gender = ratings_by_gender.loc[popular_movies]
    top_movies_individuals_tagged_as_female = ratings_by_gender.sort_values(by='F', ascending=False)
    print("Top rated movies by individuals_tagged_as_female \n", top_movies_individuals_tagged_as_female.head())
    print("\n")
if __name__ == "__main__":
    movie()