python pandas读取d列中的csv分隔符

Question

我有这种类型的CSV文件：

12012;My Name is Mike. What is your's?;3;0 
1522;In my opinion: It's cool; or at least not bad;4;0
21427;Hello. I like this feature!;5;1

我想把这些数据输入dapandas.DataFrame。 但是read_csv(sep=";")由于第2行中用户生成的消息列中的分号而抛出异常（在我看来：这很酷；至少还不错）。所有剩余的列始终具有数字数据类型。

最方便的方法是什么？

Answer 1

处理不带引号的分隔符总是一件麻烦事。在这种情况下，由于已知断开的文本被三个正确编码的列包围，因此我们可以恢复。TBH，我只需要使用标准的Python阅读器，然后从中构建一个数据帧：

import csv
import pandas as pd

with open("semi.dat", "r", newline="") as fp:
    reader = csv.reader(fp, delimiter=";")
    rows = [x[:1] + [';'.join(x[1:-2])] + x[-2:] for x in reader] 
    df = pd.DataFrame(rows)

产生

       0                                              1  2  3
0  12012               My Name is Mike. What is your's?  3  0
1   1522  In my opinion: It's cool; or at least not bad  4  0
2  21427                    Hello. I like this feature!  5  1

然后我们可以立即保存并正确引用：

In [67]: df.to_csv("fixedsemi.dat", sep=";", header=None, index=False)

In [68]: more fixedsemi.dat
12012;My Name is Mike. What is your's?;3;0
1522;"In my opinion: It's cool; or at least not bad";4;0
21427;Hello. I like this feature!;5;1

In [69]: df2 = pd.read_csv("fixedsemi.dat", sep=";", header=None)

In [70]: df2
Out[70]: 
       0                                              1  2  3
0  12012               My Name is Mike. What is your's?  3  0
1   1522  In my opinion: It's cool; or at least not bad  4  0
2  21427                    Hello. I like this feature!  5  1