Question

我有这个代码，我合并了2个文件：

f1 = open('file.csv', 'r')
f2 = open(file2.csv', 'r')
f3 = open('results.csv', 'w')

c1 = csv.reader(f1)
c2 = csv.reader(f2)
c3 = csv.writer(f3)

file2 = list(c2)

for file1_row in c1:
    row = 1
    found = False
    results_row = file1_row  
    for file2_row in file2:        
        x = file2_row[1:]
        if file1_row[0] == file2_row[0]:
            results_row.append(x)
            found = True
            break
    row += 1
    if not found:
        results_row.append('Not found')     
    c3.writerow(results_row)

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

输出是：

455, E+13, 5.05, 12, 378, BDAP, BT28, I, NSW, ['0.000000', '20140723', '20170803']

484, E+13, 5.05, 2.0, 204, LAP, 3G2, A, NSW, ['2.980000', '20150714', '20180217']

如何从添加的字段中删除“[]”和“'”？我希望输出为：

455, E+13, 5.05, 12, 378, BDAP, BT28, I, NSW, 0.000000, 20140723, 20170803

484, E+13, 5.05, 2.0, 204, LAP, 3G2, A, NSW, 2.980000, 20150714, 20180217

Answer 1

您要将列表附加到列表中。你真正想做的是extend第一个列表与第二个列表中的每个项目：

>>> c1 = [1, 2, 3]
>>> c2 = ['a', 'b']
>>> c1.append(c2)
>>> c1
[1, 2, 3, ['a', 'b']]
>>> c1 = [1, 2, 3]
>>> c1.extend(c2)
>>> c1
[1, 2, 3, 'a', 'b']

请参阅sequence operations

Answer 2

正如@JoshSmeaton所说，使用extend而不是append可以实现。

我只是在你已经获得嵌套列表的情况下发布另一种方法，并且不能改变列表添加新元素的方式。

flatList = []

def unfold(X):
    for x in X:
        if isinstance(x, list):
            unfold(x)
        else:
            flatList.append(x)

输入：

nestedList = [1, 2, [3, 4, 5]]
unfold(nestedList)
print(flatList)

输出：

[1, 2, 3, 4, 5]

从python中的csv输出中划分括号

2 个答案: