比較兩個CSV文件中的值，附加價值爲文本文件

Question

我有三個文件。我想比較列表中水果和匹配的水果，我想將匹配的水果附加到Append.txt文件，然後按升序排序。

test1.csv

CustID,Name,Count,Item,Date 
23,Smith,8,apples,08/12/2010 
1,Jones,8,banana,03/26/2009 
15,Miller,2,cookie dough,03/27/2009 
6,Fisher,8,oranges,06/09/2011 

test2.csv

FRUIT,Amount,Aisle 
oranges,1,1 
apples,1,1 
pears,1,1 

Append.txt

Fruit,Total,Aisle 
cherries,1,1 
dates,2,1 
grapes,5,1 
kiwis,2,2 
peaches,2,2 
plums,1,1 
watermelon1,2 

代碼：

import csv 

# Iterate through both reader1 and reader2, compare common row, and append matching column data to test.txt in its matching column 
with open("C:\\Test\\Append.txt", 'a') as f: 
    reader1 = csv.reader(open("C:\\Test\\test1.csv", 'rb'), delimiter=',') 
    row1 = reader1.next() 
    reader2 = csv.reader(open("C:\\Test\\test2.csv", 'rb'), delimiter=',') 
    row2 = reader2.next() 
    if (row1[3] == row2[0]): 
     print "code to append data from row1[0] to test.txt row[0] goes here" 

f.close() 
exit 

print "code to sort test.txt ascending on column[0] goes here" 

我的初始腳本不起作用。檢查後我可以看到，代碼只比較行1與行1，行2與2等，我真的希望它比較所有行（行1與行1，行1與行2，行2與行1，行2與第2行等）。在運行主腳本之後，測試文件可以填充沒有記錄或最多5條記錄。追加文件可以是空的或有數百個記錄。使用python 2.7。

我也不能確定如何在完成時按升序排序文件。

Answer 1

使用sets。先讀取兩個CSV文件，然後收集行中的成果。

然後使用set intersections查找這兩個文件共有的所有水果，將這些水果從Append.txt文件中添加到該水果中，排序並將所有水果寫回文件。

import csv 

# collect the fruits of both CSV files 
with open('c:/Test/test1.csv', 'rb') as test1: 
    reader = csv.reader(test1) 
    next(reader, None) # ignore header 
    test1_fruit = set(row[3] for row in reader) 
with open('c:/Test/test2.csv', 'rb') as test2: 
    reader = csv.reader(test2) 
    next(reader, None) # ignore header 
    test2_fruit = set(row[0] for row in reader) 

# Read all the fruit from Append 
with open("C:/Test/Append.txt", 'r') as append: 
    fruit = set(line.strip() for line in append if line.strip()) 

# add all fruit that are in both test1 and test2 
fruit |= test1_fruit & test2_fruit 

# write out a sorted list 
with open("C:/Test/Append.txt", 'w') as append: 
    append.write('\n'.join(sorted(fruit)))