Python：比較2個CSV文件中的3列，如果相等則輸出

Question

因此，我有兩個CSV文件，它們試圖進行比較並獲得相似項目的結果。 第一個文件hosts.csv如下所示：

Path    Filename    Size    Signature
C:\     a.txt       14kb    012345
D:\     b.txt       99kb    678910
C:\     c.txt       44kb    111213

第二個文件masterlist.csv如下所示：

Filename    Signature
b.txt       678910
x.txt       111213
b.txt       777777
c.txt       999999

如您所見，行不匹配，並且masterlist.csv始終大於hosts.csv文件。 我要搜索的唯一部分是簽名部分。 我知道這看起來像：

hosts [3] == masterlist [1]我正在尋找一種解決方案，該解決方案將為我提供以下內容（基本上是帶有新RESULTS列的hosts.csv文件）：

Path    Filename    Size    Signature    RESULTS
C:\     a.txt       14kb    012345       NOT FOUND in masterlist
D:\     b.txt       99kb    678910       FOUND in masterlist (row 1)
C:\     c.txt       44kb    111213       FOUND in masterlist (row 2)

我已經搜索了帖子，並在這里找到了類似的內容，但是由於我仍在學習python，所以我不太了解。

使用Python 3.5編輯

Answer 1

您可以嘗試以下方法：

import csv
masterlist = list(csv.reader(open('masterlist.csv')))
host = list(csv.reader(open('host.csv')))
masterlist_dict = {a:b for a, b in zip(["Filename", "Signature"], masterlist)}
final_result = [["Path", "Filename", "Size","Signature", "RESULTS"]] +
               [[path, filename, size, signature, "NOT FOUND"] 
                if signature in masterlist_dict["Signature"] 
                else [path, filename, size, signature, 
                      "FOUND (row {})".format(
                         masterlist_dict["Signature"].index(signature) 
                      for path, filename, size, signature in host]
write = csv.writer(open("new_host.csv", 'a')))
write.writerows(final_results)

Answer 2

使用csv.DictReader和csv.DictWriter對象的解決方案：

import csv

with open('hosts.csv', 'r') as hosts, open('masterlist.csv', 'r') as mlist, \
     open('result.csv', 'w', newline='') as res:

    host_reader = csv.DictReader(hosts, delimiter=' ', skipinitialspace=True)
    mlist_reader = csv.DictReader(mlist, delimiter=' ', skipinitialspace=True)
    writer = csv.DictWriter(res, fieldnames=host_reader.fieldnames + ['Result'], delimiter='\t')

    mlist_data = {r['Signature']: mlist_reader.line_num-1 for r in mlist_reader}
    fmt = '{0}FOUND in masterlist{1}'   # prepearing output format for `Result` field
    writer.writeheader()                # writing header

    for r in host_reader:
        if r['Signature'] in mlist_data:
            r['Result'] = fmt.format(""," (row "+str(mlist_data[r['Signature']])+")")
        else:
            r['Result'] = fmt.format("NOT ","")
        writer.writerow(r)

---

result.csv內容：

Path    Filename    Size    Signature   Result
C:\ a.txt   14kb    012345  NOT FOUND in masterlist
D:\ b.txt   99kb    678910  FOUND in masterlist (row 1)
C:\ c.txt   44kb    111213  FOUND in masterlist (row 2)

Answer 3

我總是希望使用pandas數據框來執行此類操作，因為它提供了廣泛的不同功能來保存和編輯.csv文件。 熊貓

df = pd.DataFrame.from_csv('1.csv')
df2 = pd.DataFrame.from_csv('2.csv')
df['result'] = 0
for i in xrange(df['signature'].__len__()):
    for j in xrange(df2['signature'].__len__()):
        if df['signature'][i] == df2['signature'][j]:
            df.loc[i, ('result')] = 'found in \'2.csv\' at row ' + str(
                df2.signature[df2.signature == df2['signature'][j]].index.tolist())
            break
df.to_csv('out.csv')

其中1.csv = hosts.csv和2.csv = masterlist.csv ，並將整個輸出另存為out.csv 。 輸出如下：

  path filename  signature                          result
0  C:\    a.txt      12345                               0
1  D:\    b.txt     678910     found in '2.csv' at row [0]
2  C:\    c.txt     111213  found in '2.csv' at row [1, 4]

我.csv -files如下所示。

首先 ： 1.csv

  path filename  signature
0  C:\    a.txt      12345
1  D:\    b.txt     678910
2  C:\    c.txt     111213

第二： 2.csv

  filename  signature
0    b.txt     678910
1    x.txt     111213
2    b.txt     777777
3    c.txt     999999
4    b.txt     111213

因此我可以查看2.csv是否存在多次簽名，並將其保存在哪里。