使用列值进行CSV比较

Question

I am trying to compare data in two csvs . csv1 will have say 100 rows(just an example) and 30 columns(fixed) csv2 will have say 1000 rows(just an example) and 30 columns (fixed)

I want to do following : 1. Find all rows in csv2 which have column value , when compared with csv1. So if column value of row 1 of CSV2 matches with row Y of csv1 , then grab those two rows, compare the data in both rows , put row of csv2 in csv and append a status if data matches or not .

I am new to python , unable to figure out whats wrong with the code below .kindly advise on the best solution and whats wrong with this code.

Python 2.7 or higher

f1 = file('db1.csv','r')
f2 = file('db2.csv', 'r')
f3 = file('output.csv', 'w')
c1 = csv.reader(f1)
# web _csv
c2 = csv.reader(f2)
# database csv
c3 = csv.writer(f3)
#result or output csv
dblist = map(tuple,c2)

for web_row in c1:
    row = 1
    for db_row in c2:
        if db_row[15] == web_row[15]:
            results_row = web_row                             
            for i in izip(web_row,db_row):
                if id(i[0]) == id(i[1]):
                    results_row.append('Matched!')
                    row = row + 1
                else:
                    results_row.append('FAILED MATCH, for {}: expected value is {} but actual is {}'.format(web_row[15],i[1],i[0]))
c3.writerow(results_row) 

f1.close()
f2.close()
f3.close()

csv1 enter image description here

csv2 : enter image description here

Answer 1

I have fond something that might be your issue. In this line: results_row = web_row you are not doing what I imagine you want to do.

What you ARE doing is creating a reference to web_row so you can change it with calls from a different name ( results_row ). I imagine you want to make a copy so that messing with results_row will not affect web_row .

To do this you can import the copy module and replace that ( results_row = web_row ) line with:

import copy

....

results_row = copy.copy(web_row)  

This should get you much closer to what you are looking for.