我如何在 Pandas python 中的每个新行之后插入空行

Question

I've a data

 0002 100789  Clearing charges       1000.00-  Pending
 0002 239890  Cheque bounce            20.00   client accepted
 0001 789652  Export docs             200.00   Bank of Italy charges

Output file should be

0002 100789  Clearing charges       1000.00-  Pending

0002 239890  Cheque bounce            20.00   client accepted

0001 789652  Export docs             200.00    Bank of Italy charges

my code

import pandas as pd
df=pd.read_fwf("C:\\csv_in\\back_trans.csv",widths=[4,9,16,15,23],header=None)
result=df.to_string(index=False,header=None)
new_file=open("C:\\csv_out\\back_trans.csv",mode="a+",encoding="utf-8")
new_file.writelines(result)
for line in new_file:
    print(line)
new_file.close()

Creating blank rows, which function I've to use. Please throw some lights on this.

Answer 1

You can use df.to_csv() to make your life a litter easier (and your code a little faster).

df.to_csv() then has an argument line_terminator . This controls what separates one row from another in the resulting .csv file.

How exactly a newline is encoded depends on your operating system. We can use os.linesep to find out the newline character for your OS (I can see here that you're running windows, but using os.linesep would be considered good practice anyway, and colleagues running a different OS will thank you).

Here's an MWE:

import os
import pandas as pd
import numpy as np

df = pd.DataFrame(np.random.randint(0, 10, size=(10, 3))) 

df.to_csv("C:\\csv_out\\back_trans.csv", line_terminator=os.linesep*2)

This gave me the file contents as

❯ cat C:\\csv_out\\back_trans.csv 
,0,1,2

0,4,3,4

1,1,1,8

2,4,7,1

3,3,3,7

4,8,5,0

5,7,5,3

6,1,1,0

7,0,3,4

8,1,7,1

9,1,2,9