如何读取特定数据并写入csv文件

Question

我在xml文件中有数据，我正在读取3列：price , name , calories

XML 数据

<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<price>$5.95</price>
<name>Belgian Waffles</name>
<desc>Two of our famous Belgian Waffles with plenty of real maple syrup</desc>
<calories>650</calories>
</row>
<row>
<index>1</index>
<price>$7.95</price>
<name>Strawberry Belgian Waffles</name>
<desc>Light Belgian waffles covered with strawberries and whipped cream</desc>
<calories>900</calories>
</row>
<row>
<index>2</index>
<price>$8.95</price>
<name>Berry-Berry Belgian Waffles</name>
<desc>Light Belgian waffles covered with an assortment of fresh berries and whipped cream</desc>
<calories>900</calories>
</row>
<row>
<index>3</index>
<price>$4.50</price>
<name>French Toast</name>
<desc>Thick slices made from our homemade sourdough bread</desc>
<calories>600</calories>
</row>
<row>
<index>4</index>
<price>$6.95</price>
<name>Homestyle Breakfast</name>
<desc>Two eggs, bacon or sausage, toast, and our ever-popular hash browns</desc>
<calories>950</calories>
</row>
</data>

法典：

import xml.etree.ElementTree as ET
parse_xml = ET.parse('/content/sample_data/xyz.xml')
get_root_element = parse_xml.getroot()

for data in get_root_element.findall('row'):
prc = data.find('price')
nm  = data.find('name')
cal = data.find('calories')
temp = prc.text + ',' +  nm.text + ',' + cal.text
print(temp)

上面的代码给了我数据，但需要将这些数据存储到 csv 文件

我需要如何为此编写逻辑。可以用pandas / csv

需要将我的标头也添加到该csv文件中

标题 ：price , name , calories

Answer 1

@kiric8494的解决方案已经足够好了，你可以坚持下去。您也可以使用更短的csv.DictWriter来实现它：

import xml.etree.ElementTree as ET
from csv import DictWriter
parse_xml = ET.parse(r"/content/sample_data/xyz.xml")
root = parse_xml.getroot()
with open(r"/content/sample_data/abc.csv", "w", newline="") as f:
writer = DictWriter(f, fieldnames=("price", "name", "calories"), extrasaction="ignore")
writer.writeheader()
writer.writerows({e.tag: e.text for e in row} for row in root)

基本上，我们设置DictWriter忽略除price、name和calories之外的所有字段，然后将生成器传递给.writerows()，后者构造<row>的所有子节点的字典，其中键是标签，值是文本。

Answer 2

感谢您的解决方案@ewz93

我以以下方式完成

import xml.etree.ElementTree as ET
import csv
parse_xml = ET.parse('/content/sample_data/xyz.xml')
get_root_element = parse_xml.getroot()
final_data_set = [] # [ [],[],[] ]
for data in get_root_element.findall('row'):
temp = []
prc = data.find('price')
nm  = data.find('name')
cal = data.find('calories')
temp=[prc.text + ',' +  nm.text +  ',' + cal.text]
final_data_set.append(temp)
headers = ['price','name','calories']
with open('/content/sample_data/abc.csv','w') as wr:
csv_wr = csv.writer(wr)
csv_wr.writerow(headers)
for elem in final_data_set:
for item in elem:
csv_wr.writerow(item.split(','))

Answer 3

我只是将值放在列表中并从中创建数据帧：

import xml.etree.ElementTree as ET
import pandas as pd
parse_xml = ET.parse('/content/sample_data/xyz.xml')
get_root_element = parse_xml.getroot()
prc_list = []
nm_list = []
cal_list = []
for data in get_root_element.findall('row'):
prc_list.append(data.find('price'))
nm_list.append(data.find('name'))
cal_list.append(data.find('calories'))
df = pd.DataFrame({"price": prc_list, "name": nm_list, "calories": cal_list})
df.to_excel("your_file_name.xlsx") # or if you really want a CSV use df.to_csv("your_file_name.xlsx")

这可能不是最漂亮的解决方案，因为还有 pandas.read_xml()，因此您可能可以通过直接将 XML 读取到 DataFrame 中，然后将其直接写入 CSV 来缩短它并避免使用 etree。