合並具有公共列但長度不均勻的兩個csv文件

Question

我有兩個csv文件：csv文件1包含以下內容：

California,C1,G1,K1,Dine-In,B,25
California,C2,G2,K1,Dine-In,A,8
Hawaii,H1,J1,L1,Dine-In,A,22
Hawaii,H2,J2,L2,Dine-In,A,20

CSV文件2包含：

Hawaii,10
California,20

我希望輸出為：

California,C1,G1,K1,Dine-In,B,25,20
California,C2,G2,K1,Dine-In,A,8,20
Hawaii,H1,J1,L1,Dine-In,A,22,10
Hawaii,H2,J2,L2,Dine-In,A,20,10

我已經完成了代碼：

with open(r'file 1.csv', 'r') as f:
    r = csv.reader(f)
    dict2 = {row[0]: row[1:] for row in r}

with open(r'file 2.csv','r') as f:
    r = csv.reader(f)
    dict1 = OrderedDict((row[0], row[1:]) for row in r)

result = OrderedDict()
for d in (dict1, dict2):
    for key, value in d.iteritems():
        result.setdefault(key, []).extend(value)

with open('combined data.csv', 'wb') as f:
    w = csv.writer(f)
    for key, value in result.iteritems():
        w.writerow([key] + value)

但是它給我的輸出是：

California,C1,G1,K1,Dine-In,B,25
California,C2,G2,K1,Dine-In,A,8
Hawaii,H1,J1,L1,Dine-In,A,22
Hawaii,H2,J2,L2,Dine-In,A,20
Hawaii,10
California,20

有任何想法嗎？

Answer 1

您只需要將file 2.csv作為字典加載，然后在讀取file 1.csv時將其附加到每一行，如下所示：

import csv

with open(r'file 2.csv','rb') as f_file2:
    dict2 = {row[0]: row[1:] for row in csv.reader(f_file2)}

with open(r'file 1.csv', 'rb') as f_file1, open('combined data.csv', 'wb') as f_output:
    csv_output = csv.writer(f_output)

    for row in csv.reader(f_file1):
        csv_output.writerow(row + dict2[row[0]])

給你：

California,C1,G1,K1,Dine-In,B,25,20
California,C2,G2,K1,Dine-In,A,8,20
Hawaii,H1,J1,L1,Dine-In,A,22,10
Hawaii,H2,J2,L2,Dine-In,A,20,10

Answer 2

熊貓解決方案

import pandas pd

df1 = pd.read_csv('file1.csv', header=None)
df2 = pd.read_csv('file2.csv', header=None)
res = pd.merge(df1, df2, on=0)
res.to_csv('combined.csv', header=None, index=False)

combined.csv ：

California,C1,G1,K1,Dine-In,B,25,20
California,C2,G2,K1,Dine-In,A,8,20
Hawaii,H1,J1,L1,Dine-In,A,22,10
Hawaii,H2,J2,L2,Dine-In,A,20,10

分步

將第一個文件讀入數據框：

df1 = pd.read_csv('file1.csv', header=None)

看起來像這樣：

            0   1   2   3        4  5   6
0  California  C1  G1  K1  Dine-In  B  25
1  California  C2  G2  K1  Dine-In  A   8
2      Hawaii  H1  J1  L1  Dine-In  A  22
3      Hawaii  H2  J2  L2  Dine-In  A  20

對第二個文件執行相同的操作：

df2 = pd.read_csv('file2.csv', header=None)

結果是：

            0   1
0      Hawaii  10
1  California  20

在第0列合並：

res = pd.merge(df1, df2, on=0)

現在， res看起來像這樣：

            0 1_x   2   3        4  5   6  1_y
0  California  C1  G1  K1  Dine-In  B  25   20
1  California  C2  G2  K1  Dine-In  A   8   20
2      Hawaii  H1  J1  L1  Dine-In  A  22   10
3      Hawaii  H2  J2  L2  Dine-In  A  20   10

最后，寫入沒有標題和索引的csv文件：

res.to_csv('combined.csv', header=None, index=False)