熊猫：用距离矩阵连接数据框

Question

我尝试连接两个Pandas DataFrame，但是连接错误。

初始数据集如下：

private val viewModel: AFragmentVM by activityViewModels()

然后我根据x和y坐标（最后两列）在每个孔之间生成一个欧式距离：

df
>>>
            well    qoil    cum_oil         wct     top_perf    bot_perf    st  x       y
    5233    101     259     3.684131e+05    97      -2352.13    -2359.12    0   517228  5931024
    12786   102     3495    1.369303e+06    5.47    -2352.92    -2566.81    0   517192  5927187
    13062   103     2691    1.353718e+06    0.5     -2377.93    -2581.73    0   517731  5926430
    . . . .
65 rows × 9 columns

并接收65x65矩阵（pandas.core.frame.DataFrame类型），其中包含每个孔之间的距离

from sklearn.neighbors import DistanceMetric
dist = DistanceMetric.get_metric('euclidean')
loc = pd.DataFrame(dist.pairwise(df[['x','y']].to_numpy()),
             columns=df.well.unique(), index=df.well.unique())

然后，我放置多余的列并连接两个数据帧：

loc
>>>
    101         102         103         . . . 
101 0.000000    152.278917  270.835312  . . .
102 151.278917  0.000000    326.310146  . . .
103 270.835312  346.310146  0.000000    . . .
. . .

结果，我没有收到65行x（9 + 65）列的数据帧，而是 130行×70列df ，例如：

df_train_prep = df.drop(['well', 'wct', 'x', 'y'], axis=1)
df2 = pd.concat([df_train_prep, loc], axis=1)

看起来有些数据在右边连接，但有些数据移到了底部。而且，出现了奇怪的NaN值。 请帮我了解我在做什么错。

Answer 1

    x   y   0           1           2           3           4
0   0   0   0.000000    1.414214    2.828427    4.242641    5.656854
1   1   1   1.414214    0.000000    1.414214    2.828427    4.242641
2   2   2   2.828427    1.414214    0.000000    1.414214    2.828427
3   3   3   4.242641    2.828427    1.414214    0.000000    1.414214
4   4   4   5.656854    4.242641    2.828427    1.414214    0.000000

输出：

class pizzas extends Component {
  state ={
    pizzas: [
      {id:1, name: 'Chicken Curry', ingredients: 'Red onions, bell peppers, chicken, pineapple, mozzarella, tomato sauce, curry, chili peppers', price: '3100', image: chickenCurry },
      {id:2, name: 'Pepperoni Fresh', ingredients: 'Pepperoni, mozzarella, green peppers, pizza sauce', price: '2700', image: pepperoniFresh },
      {id:3, name: 'Chicken BBQ', ingredients: 'Chicken, red onions, corn, mozzarella, bbq sauce, tomato sauce', price: '2700', image: chickenBbq },
      {id:4, name: 'Shawarma Pizza', ingredients: 'Mayonnaise & ketchup, spicy chicken, red onions, tomatoes, mozzarella', price: '3100', image: sharwarmaPizza },
      {id:5, name: 'Chicken Suya', ingredients: 'Mayonnaise, spicy sauce, spicy chicken, bell peppers, red onions, suya sauce, tomato sauce, mozzarella, suya spice', price: '2700', image: chickenSuya },
      {id:6, name: 'Pepperoni', ingredients: 'Pepperoni, mozzarella, tomato sauce', price: '2700', image: pepperoni },
      {id:7, name: 'Beef Suya', ingredients: 'Mayonnaise, spicy sauce, spicy meatballs, bell peppers, red onions, mozzarella, suya sauce, tomato sauce, suya spice', price: '2700', image: beefSuya },
      {id:8, name: 'Chicken Supreme', ingredients: 'Spicy sauce, chicken and spicy chicken, mushrooms, bell peppers, olives, red onions, mozzarella, tomato sauce', price: '3100', image: chickenSupreme },
      {id:9, name: 'Sweet Chili Chicken', ingredients: 'Spicy sauce, chicken, chili pepper, mozzarella, sweet chili sauce, tomato sauce', price: '2700', image: chickenCurry },
      {id:10, name: 'Spicy Mixed Pizza', ingredients: 'Spicy sauce, spicy meatballs, spicy chicken, chili pepper, corn, mozzarella, buffalo sauce, tomato sauce', price: '3100', image: spicyMixedPizza },
      {id:11, name: 'Margherita', ingredients: 'Mozarella, tomato sauce', price: '2200', image: margherita },
      {id:12, name: 'Super Meaty', ingredients: 'Chicken, pepperonni, sausages, mozzarella, tomato sauce', price: '3100', image: superMeaty },
      {id:13, name: 'Cheesy Chicken', ingredients: 'Chicken, tomatoes, cheddar, mozzarella, cheese sauce', price: '2700', image: cheesyChicken },
      {id:14, name: 'Cheeseburger Pizza', ingredients: 'Beef, tomatoes, red onions, cheddar, mozzarella, mayonnaise & ketchup, tomato sauce', price: '3100', image: cheeseBurger },
      {id:15, name: 'Meaty Overload', ingredients: 'Spicy sauce, pepperonni, spicy meatballs, chicken, sausages, mozzarella, tomato sauce', price: '3400', image: meatyOverload },
      {id:16, name: 'Meaty BBQ', ingredients: 'Beef, pepperonni, sausages, mozzarella, bbq sauce, tomato sauce', price: '3100', image: meatyBbq },
      {id:17, name: 'Hawaiian', ingredients: 'Chicken, pineapple, mozzarella, sweet chili sauce, tomato sauce', price: '2700', image: hawaiian },
      {id:18, name: 'Veggie Overload', ingredients: 'Mushrooms, bell peppers, corn, olives, red onions, tomatoes, mozzarella, tomato sauce', price: '3100', image: veggieOverload }
    ],
    showModal: false,
  }
  removeModalHandler = (item)=>{
    this.setState({showModal: !this.state.showModal})
  }
  render(){
  return (
   <Aux>
   { this.state.showModal ?
     <Modal ingredients={this.state.pizzas.ingredients} image={this.state.pizzas.image} name={this.state.pizzas.name} key={this.state.pizzas.id}/>: null}
   <div className={styles.Pizza}>
     <h1>Pizza</h1>
     <div className={styles.PizzaContainer}>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={chickenCurry} alt="chickencurry"/>
          <h1>Chicken Curry</h1>
          <p>Red onions, bell peppers, chicken, pineapple, mozzarella, tomato sauce, curry, chili peppers</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button onClick={this.removeModalHandler}>Select</button>
        </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={pepperoniFresh} alt="pepperonifresh"/>
          <h1>Pepperoni Fresh</h1>
          <p>Pepperoni, mozzarella, green peppers, pizza sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
        </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={chickenBbq} alt="chickenbbq"/>
          <h1>Chicken BBQ</h1>
          <p>Chicken, red onions, corn, mozzarella, bbq sauce, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
        </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
         <img src={sharwarmaPizza} alt="sharwarma"/>
          <h1>Shawarma Pizza</h1>
          <p>Mayonnaise & ketchup, spicy chicken, red onions, tomatoes, mozzarella</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
        </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={chickenSuya} alt="chickensuya"/>
          <h1>Chicken Suya</h1>
          <p>Mayonnaise, spicy sauce, spicy chicken, bell peppers, red onions, suya sauce, tomato sauce, mozzarella, suya spice</p>
         </div>
        <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
        </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
           <img src={pepperoni} alt="pepperoni"/>
           <h1>Pepperoni</h1>
           <p>Pepperoni, mozzarella, tomato sauce</p>
         </div> 
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={beefSuya} alt="beefsuya"/>
          <h1>Beef Suya</h1>
          <p>Mayonnaise, spicy sauce, spicy meatballs, bell peppers, red onions, mozzarella, suya sauce, tomato sauce, suya spice</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={chickenSupreme} alt="chickensupreme"/>
          <h1>Chicken Supreme</h1>
          <p>Spicy sauce, chicken and spicy chicken, mushrooms, bell peppers, olives, red onions, mozzarella, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
         <img src={sweetChiliChicken} alt="sweetchillichicken"/>
          <h1>Sweet Chili Chicken</h1>
          <p>Spicy sauce, chicken, chili pepper, mozzarella, sweet chili sauce, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={spicyMixedPizza} alt="spicymixed"/>
          <h1>Spicy Mixed Pizza</h1>
          <p>Spicy          sauce, spicy meatballs, spicy chicken, chili pepper, corn, mozzarella, buffalo sauce, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={margherita} alt="margherita"/>
          <h1>Margherita</h1>
          <p>Mozzarella, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,200</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={superMeaty} alt="supermeaty"/>
          <h1>Super Meaty</h1>
          <p>Chicken, pepperonni, sausages, mozzarella, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={cheesyChicken} alt="cheesychicken"/>
          <h1>Cheesy Chicken</h1>
          <p>Chicken, tomatoes, cheddar, mozzarella, cheese sauce</p>
         </div> 
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={cheeseBurger} alt="cheeseburger"/>
          <h1>Cheeseburger Pizza</h1>
          <p>Beef, tomatoes, red onions, cheddar, mozzarella, mayonnaise & ketchup, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={meatyOverload} alt="meatyoverload"/>
          <h1>Meaty Overload</h1>
          <p>Spicy sauce, pepperonni, spicy meatballs, chicken, sausages, mozzarella, tomato sauce</p>
         </div> 
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,400</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={meatyBbq} alt="meatybbq"/>
          <h1>Meaty BBQ</h1>
          <p>Beef, pepperonni, sausages, mozzarella, bbq sauce, tomato sauce</p>
         </div> 
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦3,100</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={hawaiian} alt="hawaiin"/>
          <h1>Hawaiian</h1>
          <p>Chicken, pineapple, mozzarella, sweet chili sauce, tomato sauce</p>
         </div>
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
       <div className={styles.PizzaCard}>
         <div className={styles.PizzaCardHeader}>
          <img src={veggieOverload} alt="veggie"/>
          <h1>Veggie Overload</h1>
          <p>Mushrooms, bell peppers, corn, olives, red onions, tomatoes, mozzarella, tomato sauce</p>
         </div> 
         <div className={styles.PizzaCardFooter}>
          <h3>from ₦2,700</h3>
          <button>Select</button>
         </div>
       </div>
     </div>
   </div>
   </Aux>
  )
}
}
export default pizzas;

如您所见，沿行距是一个对称矩阵。