将数据框保存为 pandas 中的 csv/文本文件，无需行编号

Question

我使用 pandas 中的文本文件创建了一个数据框。

df = pd.read_table('inputfile.txt',names=['Line'])

当我做df

Line
0   17/08/31 13:24:48 INFO spark.SparkContext: Run...
1   17/08/31 13:24:49 INFO spark.SecurityManager: ...
2   17/08/31 13:24:49 INFO spark.SecurityManager: ...
3   17/08/31 13:24:49 INFO spark.SecurityManager: ...
4   17/08/31 13:24:49 INFO util.Utils: Successfull...
5   17/08/31 13:24:49 INFO slf4j.Slf4jLogger: Slf4...
6   17/08/31 13:24:49 INFO Remoting: Starting remo...
7   17/08/31 13:24:50 INFO Remoting: Remoting star...
8   17/08/31 13:24:50 INFO Remoting: Remoting now ...
9   17/08/31 13:24:50 INFO util.Utils: Successfull...   

现在我想将此文件另存为csv

df.to_csv('outputfile')

我得到的结果是这样的

0,17/08/31 13:24:48 INFO spark.SparkContext: Running Spark version 1.6.0
1,17/08/31 13:24:49 INFO spark.SecurityManager: Changing view acls to: user1
2,17/08/31 13:24:49 INFO spark.SecurityManager: Changing modify acls to: user1
3,17/08/31 13:24:49 INFO spark.SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(user1);
4,17/08/31 13:24:49 INFO util.Utils: Successfully started service 'sparkDriver' on port 17101.
5,17/08/31 13:24:49 INFO slf4j.Slf4jLogger: Slf4jLogger started
6,17/08/31 13:24:49 INFO Remoting: Starting remoting
7,17/08/31 13:24:50 INFO Remoting: Remoting started; listening on addresses :
8,17/08/31 13:24:50 INFO Remoting: Remoting now listens on addresses: 
9,17/08/31 13:24:50 INFO util.Utils: Successfully started service 'sparkDriverActorSystem' on port 100033.

我希望我的输出是

17/08/31 13:24:48 INFO spark.SparkContext: Running Spark version 1.6.0
17/08/31 13:24:49 INFO spark.SecurityManager: Changing view acls to: user1
17/08/31 13:24:49 INFO spark.SecurityManager: Changing modify acls to: user1
17/08/31 13:24:49 INFO spark.SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(user1);
17/08/31 13:24:49 INFO util.Utils: Successfully started service 'sparkDriver' on port 17101.
17/08/31 13:24:49 INFO slf4j.Slf4jLogger: Slf4jLogger started
17/08/31 13:24:49 INFO Remoting: Starting remoting
17/08/31 13:24:50 INFO Remoting: Remoting started; listening on addresses :
17/08/31 13:24:50 INFO Remoting: Remoting now listens on addresses: 
17/08/31 13:24:50 INFO util.Utils: Successfully started service 'sparkDriverActorSystem' on port 100033.

我尝试了如下几种方法，但仍然得到相同的结果，而不是我想要的输出。

np.savetxt(r'np.txt', df.Line, fmt='%d')

df.to_csv(sep=' ', index=False, header=False)

Answer 1

考虑到特殊情况，詹姆斯的回答可能是正确的。但是，标准行为是pandas将行号作为一列，前面没有标题。要删除它，只需将index=参数设置为False：

df.to_csv("outfile.csv", index=False)

（编辑：已更正，根据 @Haagimus 正确指出的内容，不会误导任何人。）

Answer 2

看起来该数字可能是Line列中字符串的一部分。您可以使用以下命令将前导数字和空格替换为空，并将其输出到没有索引的文件中：

df.Line.str.replace('^\d+ +','').to_csv('outputfile.csv', index=False, header=False)