import matplotlib.pyplot as plt
import json
movies= json.load(open('movies.json',encoding='utf-8'))
rating=[]
durations=[]
for m in movies:
    rating.append(m['rating'])
    durations.append(m['duration'])
plt.title("评分分布")        
plt.xlabel("评分")    
plt.figure(figsize=(8,5))
plt.hist(rating,bins=5,color='blue')
plt.savefig('q4_3a_hist.png',dpi=150)