Question

我在弄清楚该个人项目的具体位置时遇到了麻烦，我希望这个社区可以帮助我创建一个Python脚本来处理这些数据。

我有一个CSV文件，其中包含动物救助时喂给狗的饭食的清单，并与狗窝号关联：

源CSV-mealsandtreats.csv

blank_column,Kennel_Number,Species,Food,Meal_ID
,1,Dog,Meal,11.2
,5,Dog,Meal,45.2
,3,Dog,Meal,21.4
,4,Dog,Meal,17
,2,Dog,Meal,11.2
,4,Dog,Meal,21.4
,6,Dog,Meal,17
,2,Dog,Meal,45.2

我还有第二个CSV文件，该文件提供了一个密钥，可将餐点映射到餐点附带的食物：

用于处理密钥的餐点-MealsToTreatsKey.csv

Meals_fed,Treats_fed
10.1,2.4
11.2,2.4
13.5,3
15.6,3.2
17,3.2
20.1,5.1
21.4,5.2
35.7,7.7
45.2,7.9

我需要接受从表1交付的每种餐食类型（例如，删除重复的条目），找到相关的零食类型，然后在每次为特定的狗窝提供零食时创建一个单独的条目。最终结果应如下所示：

结果CSV-mealsandtreats.csv

blank_column,Kennel_Number,Species,Food,Meal_ID
,1,Dog,Meal,11.2
,5,Dog,Meal,45.2
,3,Dog,Meal,21.4
,4,Dog,Meal,17
,2,Dog,Meal,11.2
,4,Dog,Meal,21.4
,6,Dog,Meal,17
,2,Dog,Meal,45.2
,1,Dog,Treat,2.4
,5,Dog,Treat,7.9
,3,Dog,Treat,5.2
,4,Dog,Treat,3.2
,1,Dog,Treat,2.4
,4,Dog,Treat,5.2

宁愿使用csv模块而不是Pandas来执行此操作，但如有必要，我愿意使用Pandas。

到目前为止，我仅打开CSV就有一些代码，但是我真的对下一步的工作很执着：

import csv

with open('./meals/results/foodToTreats.csv', 'r') as t1, 
open('./results/food.csv', 'r') as t2:
    key = t1.readlines()
    map = t2.readlines()

with open('./results/food.csv', 'w') as outFileF:
        for line in map:
            if line not in key:
                outFileF.write(line)

with open('./results/foodandtreats.csv', 'w') as outFileFT:
        for line in map:
            if line not in key:
                outFileFT.write(line)

因此，基本上，我只需要获取第二张表中的每个请客条目，在第一张表中搜索匹配的相关食品条目，查找与该条目相关的狗窝编号，然后将其写入第一张表中。

用伪代码尽我最大的努力，例如：

for x in column 0,y: 
    y,1 = Z 

food = x
treat = y
kennel_number = z

when x,z: 
    writerows('', {'kennel_number"}, 'species', '{food/treat}',  
{'meal_id"})

更新：这是我正在使用的确切代码，这要感谢@wwii。看到一个小错误：

import csv
import collections

treats = {}
with open('mealsToTreatsKey.csv') as f2:
    for line in f2:
        meal,treat = line.strip().split(',')
        treats[meal] = treat

new_items = set()
Treat = collections.namedtuple('Treat', ['blank_column','Kennel_Number','Species','Food','Meal_ID'])

with open('foodandtreats.csv') as f1:
    reader = csv.DictReader(f1)
    for row in reader:
        row['Food'] = 'Treat'
        row['Meal_ID'] = treats[row['Meal_ID']]
        new_items.add(Treat(**row))
    fieldnames = reader.fieldnames

with open('foodandtreats.csv', 'a') as f1:
    writer = csv.DictWriter(f1, fieldnames)
    for row in new_items:
        writer.writerow(row._asdict())

除一个小错误外，这非常有效。所写的第一行新记录不是一行一行开始的： enter image description here

Answer 1

制作一本字典，将饭菜映射成美食

treats = {}
with open(treatfile) as f2:
    for line in f2:
        meal,treat = line.strip().split(',')
        treats[meal] = treat

遍历进餐文件并创建一组新条目。对新项目使用namedtuple。

import collections
new_items = set()
Treat = collections.namedtuple('Treat', ['blank_column','Kennel_Number','Species','Food','Meal_ID'])

with open(mealfile) as f1:
    reader = csv.DictReader(f1)
    for row in reader:
        row['Food'] = 'Treat'
        row['Meal_ID'] = treats[row['Meal_ID']]
        new_items.add(Treat(**row))
    fieldnames = reader.fieldnames

（再次）打开膳食文件以添加并写入新条目

with open(mealfile, 'a') as f1:
    writer = csv.DictWriter(f1, fieldnames)
    for row in new_items:
        writer.writerow(row._asdict())

如果餐文件没有以换行符结尾，则需要在写入新的treat行之前添加一个。由于您可以控制文件，因此只需确保文件始终以空行结尾。

关联来自两个CSV的数据，并使用Python将数据写入第一个CSV

1 个答案: