在多个 CSV 中搜索一个特定值

Question

我有一个列出水果和数量的 CSV 文件目录，我想搜索所有这些文件并创建一个只有特定水果（例如“苹果”）的新 CSV。

list1.csv

| Name     | Qty |
| -------- | --- |
| apple    |15   | 
| apple    |50   |
| mango    |20   | 
| grapes   |49   |

list2.csv

| Name     | Qty |
| -------- | --- |
| apple    |25   | 
| apple    |50   |
| Banana   |34   |
| mango    |20   | 
| grapes   |49   |

list3.csv

| Name     | Qty |
| -------- | --- |
| apple    |125   | 
| apple    |530   |
| mango    |20   | 
| grapes   |49   |

我想要，“苹果”：

new.csv

| Name     | Qty |
| -------- | --- |
| apple    |15   | 
| apple    |50   |
| apple    |25   | 
| apple    |50   |
| apple    |125  | 
| apple    |530  |

import pandas as pd
import glob, os
path = ("E:/Data/Fdata")
all_files = glob.glob(path + "/*.csv")
li=[]
for filename in all_files:
    df=pd.read_csv(filename, index_col=None, header=0)
    ndf = df[df["Name"].str.contains("Apple")]
    li.append(ndf)
    ndf.to_csv("E:/Data/Fdata/onlyapple.csv", index=True)

Answer 1

将所有 csv 文件读取到 master DataFrame
过滤你想要的“姓名”并写to_csv

import os
import pandas as pd

master = pd.DataFrame()
for file in [f for f in os.listdir(".") if f.endswith("csv")]:
    master = master.append(pd.read_csv(file), ignore_index=True)
    
master[master["Name"].eq("apple")].reset_index(drop=True).to_csv("onlyapple.csv")

onlyapple.csv:

,Name,quantity,price
0,apple,15,500
1,apple,50,400
2,apple,15,500
3,apple,50,400

Answer 2

以下是没有 Pandas 的方法：

import csv
import glob

fruit = 'apple'

final = []
header = []

for file in glob.glob('./*.csv'):
    with open(file, newline='') as f:
        reader = csv.reader(f)
        header = next(reader)  # header should be same for each file

        for row in reader:
            if row[0] == fruit:
                final.append(row)

with open('output.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerow(header)    # use the last file's header
    writer.writerows(final)

下面是如何使用 GoCSV 的命令、stack（将您的文件一个堆叠在一起）和 filter（只过滤掉你想要的行）：

gocsv stack *.csv | gocsv filter -c Name -eq apple

在多个 CSV 中搜索一个特定值

Search multiple CSVs for one particular value

python

csv

glob

append

pandas

onlyapple.csv: