如何在Numpy的Dataframe中插入值？

Question

我是一个新的程序员，刚刚开始学习一些关于numpy的知识。我想将从网络抓取的信息插入到一个数据框架中。这是我到目前为止想出的。

from urllib2 import urlopen as uReq
from bs4 import BeautifulSoup as soup

import numpy as np
import pandas as  pd
from pandas import Series, DataFrame


my_url = 'http://www.bestbuy.com/site/searchpage.jsp?st=laptops&_dyncharset=UTF-8&id=pcat17071&type=page&sc=Global&cp=1&nrp=&sp=&qp=&list=n&af=true&iht=y&usc=All+Categories&ks=960&keys=keys'

uClient = uReq(my_url)
page_html = uClient.read()
uClient.close()
page_soup = soup(page_html, "html.parser")
containers = page_soup.find_all("div",{"class":"row"})


DF_obj = DataFrame(np.arange(len(containers)*2).reshape((len(containers),2)), columns = ['Name', 'Price'])#index=['row 1', 'row 2', 'row 3', 'row 4', 'row 5', 'row 6'], columns=['column 1', 'column 2', 'column 3', 'column 4', 'column 5', 'column 6', ]

#print(DF_obj)
for container in containers:


   try:
      title_container = container.find_all("h4")
      product_name = title_container[0].text

      price_container = container.find_all("div", {"class", "pb-hero-price pb-purchase-price"})
      product_price = price_container[0].text
      #print("Product Name: "+ product_name)
      #print("Price:"+ product_price)
      DF_obj['Name'] = product_name # Here is the problem
      DF_obj['Price'] = product_price# Here is the problem
   except Exception:
       pass

print(DF_obj)

我现在所做的只是允许显示最后一次擦伤的产品。这是因为我使产品的名称和价格相等于整个专栏。我想找到一种方法，使它只等于I‘’th列，迭代到下一列。

基本上，我想在(容器，1)和(容器，2)上插入一个值。由于容器将迭代，下一个名称将转到下一列。这样做的语法是什么？

下面是一些可以让你们直观地看到正在发生的事情的输出：

  Name    Price
0   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
1   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
2   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
3   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
4   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
5   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
6   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
7   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
8   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
9   Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
10  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
11  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
12  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
13  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
14  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99
15  Dell - Inspiron 2-in-1 13.3" Touch-Screen Lapt...  $849.99

既然你有了主意，就剪掉一些输出.

这里是我想要的，除了在数据框架内。

Product Name: Dell - XPS 2-in-1 13.3" Touch-Screen Laptop - Intel Core i7 - 16GB Memory - 512GB Solid State Drive - Silver
Price:$241.99
Product Name: HP - 15.6" Laptop - AMD A6-Series - 4GB Memory - 500GB Hard Drive - Black
Price:$241.99
Product Name: Dell - Inspiron 15.6" Touch-Screen Laptop - Intel Core i3 - 6GB Memory - 1TB Hard Drive - Black
Price:$349.99
Product Name: HP - 15.6" Laptop - Intel Core i5 - 8GB Memory - 2TB Hard Drive - Textured linear gradient grooves in black
Price:$449.99
Product Name: Lenovo - Ideapad 110s 11.6" Laptop - Intel Celeron - 2GB Memory - 32GB eMMC Flash Memory - White
Price:$169.99
Product Name: HP - 15.6" Laptop - Intel Core i5 - 8GB Memory - 1TB Hard Drive - HP finish in jet black
Price:$399.99
Product Name: Lenovo - Flex 4 14 2-in-1 14" Touch-Screen Laptop - Intel Pentium - 4GB Memory - 500GB Hard Drive - Black
Price:$349.99
Product Name: Lenovo - 15.6" Laptop - Intel Core i3 - 6GB Memory - 1TB Hard Drive - Ebony black
Price:$312.99
Product Name: Lenovo - Flex 4 1130 2-in-1 11.6" Touch-Screen Laptop - Intel Celeron - 2GB Memory - 64GB eMMC Flash Memory
Price:$229.99
Product Name: HP - Spectre x360 2-in-1 13.3" Touch-Screen Laptop - Intel Core i7 - 8GB Memory - 256GB Solid State Drive - Natural silver
Price:$1,129.99

谢谢。

Answer 1

更新的代码。集装箱的清单不完全正确。class=row的div标记比您需要的要高一点。现在，遍历所有list-item标记并将它们逐行添加到数据帧的for循环。

my_url = 'http://www.bestbuy.com/site/searchpage.jsp?st=laptops&_dyncharset=UTF-8&id=pcat17071&type=page&sc=Global&cp=1&nrp=&sp=&qp=&list=n&af=true&iht=y&usc=All+Categories&ks=960&keys=keys'

uClient = uReq(my_url)
page_html = uClient.read()
uClient.close()
page_soup = soup(page_html, "html.parser")

#This is the div tag that contains each of the products listed on the page
containers = page_soup.find_all("div",{'class':'list-item'})

#Just a check to make sure all the products are found
print len(containers)

#Create an empty dataframe, It can be populated later, no need for a fixed 
#structure
DF_obj = DataFrame(columns = ['Name', 'Price'])


#we want to loop over the containers, but during each loop, we also want to 
#track the loop number we are on, this will help us enter data into the 
#dataframe, so we wrap containers with enumerate()

# in this situation index = loop count, container = value from containers list
for index,container in enumerate(containers):
   try:
      #These two you provided
      title_container = container.find_all("h4")
      price_container = container.find_all("div", {"class", "pb-hero-price pb-purchase-price"})

      #Now that we found the info, we insert it into the data frame. This 
      #can be done with DF_obj.loc[row#,column Name], and our df is updated
      #for every container
      DF_obj.loc[index,'Name'] = title_container[0].text
      DF_obj.loc[index, 'Price'] = price_container[0].text
   except Exception:
       pass
print DF_obj

和数据

                                                 Name      Price
0   HP - 15.6" Laptop - AMD A6-Series - 4GB Memory...    $241.99
1   HP - 15.6" Laptop - Intel Core i5 - 8GB Memory...    $399.99
2   Lenovo - Ideapad 110s 11.6" Laptop - Intel Cel...    $169.99
3   Dell - Inspiron 15.6" Touch-Screen Laptop - In...    $349.99
4   HP - 15.6" Laptop - Intel Core i5 - 8GB Memory...    $449.99
5   HP - 17.3" Laptop - Intel Core i7 - 8GB Memory...    $529.99
6   Dell - Inspiron 11.6" Laptop - Intel Celeron -...    $174.99
7   Lenovo - 15.6" Laptop - AMD A6-Series - 4GB Me...    $229.99
8   Dell - Inspiron 15.6" Touch-Screen Laptop - In...    $349.99
9   Lenovo - Flex 4 14 2-in-1 14" Touch-Screen Lap...    $349.99
10  Dell - Inspiron 17.3" Laptop - AMD A9-Series -...    $506.99
11  Dell - Inspiron 17.3" Laptop - Intel Core i7 -...    $938.99
12  Samsung - 11.6" Chromebook - Intel Celeron - 4...        NaN
13  Acer - 15.6" Chromebook - Intel Celeron - 4GB ...    $219.99
14  Lenovo - Yoga 710 2-in-1 11.6" Touch-Screen La...    $399.99
15  Dell - Inspiron 2-in-1 17.3" Touch-Screen Lapt...    $849.99
16  HP - Spectre x360 2-in-1 13.3" Touch-Screen La...  $1,279.99
17  Asus - 2-in-1 13.3" Touch-Screen Laptop - Inte...  $1,129.99
18  HP - 15.6" Laptop - AMD A12-Series - 6GB Memor...    $299.99
19  Asus - ROG GL502VM 15.6" Laptop - Intel Core i...  $1,149.99
20  Lenovo - 15.6" Laptop - Intel Core i3 - 6GB Me...    $312.99
21  Lenovo - Flex 4 1130 2-in-1 11.6" Touch-Screen...    $229.99
22  Samsung - 12.3" Chromebook Plus - Touch Screen...    $399.00
23  HP - Spectre x360 2-in-1 13.3" Touch-Screen La...  $1,129.99