python - 如何在 pandas 中连接数据框？

Question

我通过 pymongo 将数据从 mongoDB 获取到 python，然后将其转换为 pandas dataframe

df = pd.DataFrame(list(db.dataset2.find()))

这就是 mongoDB 中数据的样子。

"dish" : [
      {
        "dish_id"          : "005" ,
        "dish_name"        : "Sandwitch",
        "dish_price"       : 50,
        "coupon_applied"   : "Yes",              
        "coupon_type"      : "Rs 20 off"
      },
      {
        "dish_id"          : "006" ,
        "dish_name"        : "Chicken Hundi",
        "dish_price"       : 125,
        "coupon_applied"   : "No",
        "coupon_type"      : "Null"

      }
   ],

我想将 pandas 数据框中的菜肴属性分成两行。这是执行此操作的代码。 (有3个菜文件)所以，我通过for循环迭代它。

for i in range(0,len(df.dish)):
data_dish = json_normalize(df['dish'][i])
print data_dish

但它给了我以下输出..

 coupon_applied   coupon_type   dish_id     dish_name       dish_price  
0            Yes   Rs 20 off     001     Chicken Biryani         120   
1             No        Null     001      Paneer Biryani         100   

coupon_applied  coupon_type     dish_id   dish_name        dish_price  
0        Yes       Rs 40 off     002     Mutton Biryani      130   
1        No          Null        004      Aaloo tikki         95   


coupon_applied   coupon_type    dish_id   dish_name        dish_price 
0     Yes         Rs 20 off      005      Sandwitch           50   
1     No             Null        006     Chicken Hundi        125   

我想要以下格式的输出..

  coupon_applied   coupon_type   dish_id     dish_name       dish_price  
0     Yes          Rs 20 off      001     Chicken Biryani      120   
1     No             Null         001      Paneer Biryani      100   
2     Yes          Rs 40 off      002     Mutton Biryani       130   
3     No             Null         004      Aaloo tikki         95   
4     Yes         Rs 20 off       005      Sandwitch           50   
5     No             Null         006     Chicken Hundi        125   

你能帮我解决这个问题吗？预先感谢:)

Answer 1

有

dishes = [json_normalize(d) for d in df['dish']]
df = pd.concat(dishes, ignore_index=True)