目录
简介
为了更好的熟练掌握pandas在实际数据分析中的应用,今天我们再介绍一下怎么使用pandas做美国餐厅评分数据的分析。
餐厅评分数据简介
数据的来源是UCI ML Repository,包含了一千多条数据,有5个属性,分别是:
userID: 用户ID
placeID:餐厅ID
rating:总体评分
food_rating:食物评分
service_rating:服务评分
我们使用pandas来读取数据:
import numpy as np path = '../data/restaurant_rating_final.csv' df = pd.read_csv(path) df
userID | placeID | rating | food_rating | service_rating | |
0 | U1077 | 135085 | 2 | 2 | 2 |
1 | U1077 | 135038 | 2 | 2 | 1 |
2 | U1077 | 132825 | 2 | 2 | 2 |
3 | U1077 | 135060 | 1 | 2 | 2 |
4 | U1068 | 135104 | 1 | 1 | 2 |
... | ... | ... | ... | ... | ... |
1156 | U1043 | 132630 | 1 | 1 | 1 |
1157 | U1011 | 132715 | 1 | 1 | 0 |
1158 | U1068 | 132733 | 1 | 1 | 0 |
1159 | U1068 | 132594 | 1 | 1 | 1 |
1160 | U1068 | 132660 | 0 | 0 | 0 |
1161 rows × 5 columns
分析评分数据
如果我们关注的是不同餐厅的总评分和食物评分,我们可以先看下这些餐厅评分的平均数,这里我们使用pivot_table方法:
mean_ratings = df.pivot_table(values=['rating','food_rating'], index='placeID', aggfunc='mean') mean_ratings[:5]
food_rating | rating | |
placeID | ||
132560 | 1.00 | 0.50 |
132561 | 1.00 | 0.75 |
132564 | 1.25 | 1.25 |
132572 | 1.00 | 1.00 |
132583 | 1.00 | 1.00 |
然后再看一下各个placeID,投票人数的统计:
ratings_by_place = df.groupby('placeID').size() ratings_by_place[:10]
placeID 132560 4 132561 4 132564 4 132572 15 132583 4 132584 6 132594 5 132608 6 132609 5 132613 6 dtype: int64
如果投票人数太少,那么这些数据其实是不客观的,我们来挑选一下投票人数超过4个的餐厅:
active_place = ratings_by_place.index[ratings_by_place >= 4] active_place
Int64Index([132560, 132561, 132564, 132572, 132583, 132584, 132594, 132608, 132609, 132613, ... 135080, 135081, 135082, 135085, 135086, 135088, 135104, 135106, 135108, 135109], dtype='int64', name='placeID', length=124)
选择这些餐厅的平均评分数据:
mean_ratings = mean_ratings.loc[active_place] mean_ratings
food_rating | rating | |
placeID | ||
132560 | 1.000000 | 0.500000 |
132561 | 1.000000 | 0.750000 |
132564 | 1.250000 | 1.250000 |
132572 | 1.000000 | 1.000000 |
132583 | 1.000000 | 1.000000 |
... | ... | ... |
135088 | 1.166667 | 1.000000 |
135104 | 1.428571 | 0.857143 |
135106 | 1.200000 | 1.200000 |
135108 | 1.181818 | 1.181818 |
135109 | 1.250000 | 1.000000 |
124 rows × 2 columns
对rating进行排序,选择评分最高的10个:
top_ratings = mean_ratings.sort_values(by='rating', ascending=False) top_ratings[:10]
food_rating | rating | |
placeID | ||
132955 | 1.800000 | 2.000000 |
135034 | 2.000000 | 2.000000 |
134986 | 2.000000 | 2.000000 |
132922 | 1.500000 | 1.833333 |
132755 | 2.000000 | 1.800000 |
135074 | 1.750000 | 1.750000 |
135013 | 2.000000 | 1.750000 |
134976 | 1.750000 | 1.750000 |
135055 | 1.714286 | 1.714286 |
135075 | 1.692308 | 1.692308 |
我们还可以计算平均总评分和平均食物评分的差值,并以一栏diff进行保存:
mean_ratings['diff'] = mean_ratings['rating'] - mean_ratings['food_rating'] sorted_by_diff = mean_ratings.sort_values(by='diff') sorted_by_diff[:10]
food_rating | rating | diff | |
placeID | |||
132667 | 2.000000 | 1.250000 | -0.750000 |
132594 | 1.200000 | 0.600000 | -0.600000 |
132858 | 1.400000 | 0.800000 | -0.600000 |
135104 | 1.428571 | 0.857143 | -0.571429 |
132560 | 1.000000 | 0.500000 | -0.500000 |
135027 | 1.375000 | 0.875000 | -0.500000 |
132740 | 1.250000 | 0.750000 | -0.500000 |
134992 | 1.500000 | 1.000000 | -0.500000 |
132706 | 1.250000 | 0.750000 | -0.500000 |
132870 | 1.000000 | 0.600000 | -0.400000 |
将数据进行反转,选择差距最大的前10:
sorted_by_diff[::-1][:10]
food_rating | rating | diff | |
placeID | |||
134987 | 0.500000 | 1.000000 | 0.500000 |
132937 | 1.000000 | 1.500000 | 0.500000 |
135066 | 1.000000 | 1.500000 | 0.500000 |
132851 | 1.000000 | 1.428571 | 0.428571 |
135049 | 0.600000 | 1.000000 | 0.400000 |
132922 | 1.500000 | 1.833333 | 0.333333 |
135030 | 1.333333 | 1.583333 | 0.250000 |
135063 | 1.000000 | 1.250000 | 0.250000 |
132626 | 1.000000 | 1.250000 | 0.250000 |
135000 | 1.000000 | 1.250000 | 0.250000 |
计算rating的标准差,并选择最大的前10个:
# Standard deviation of rating grouped by placeID rating_std_by_place = df.groupby('placeID')['rating'].std() # Filter down to active_titles rating_std_by_place = rating_std_by_place.loc[active_place] # Order Series by value in descending order rating_std_by_place.sort_values(ascending=False)[:10]
placeID 134987 1.154701 135049 1.000000 134983 1.000000 135053 0.991031 135027 0.991031 132847 0.983192 132767 0.983192 132884 0.983192 135082 0.971825 132706 0.957427 Name: rating, dtype: float64