报错NameError: name 'user_type' is not defined

repurchase_users = user_type[user_type['buy']>=2].shape[0]  
user_bought_count = df[df['behavior']=='buy'].user_id.nunique()
repurchase_rate = repurchase_users/user_bought_count
print("复购率:{:.2f}%".format(repurchase_rate*100))

sns.distplot(user_type[user_type['buy']>=2]['buy']-1,kde=False)
plt.show()

出现错误了

user_type没定义
一共就放出6行代码来，从这点代码来看，user_type确实没定义