使用python將日期列添加到csv

Question

我有以下代碼將數據輸出寫入csv文件。我想使用我用於創建文件名的yesterday.strftime變量在每行末尾添加一個日期變量。例如：

謝謝！

我的電流輸出是這樣的：

columnA

，我想加入以下列：

日期

2/5/2016

2/5/2016

。 。 。

代碼::

filepath = 'C:\\test\\' 
filename = yesterday.strftime('%Y-%m-%d') + '_' + 'test.csv' 

f = open(filename, 'wt') 
writer = csv.writer(f, lineterminator='\n') 
header = [h['name'][3:] for h in results.get('columnHeaders')] 
writer.writerow(header) 
print(''.join('%30s' % h for h in header)) 

# Write data table. 
if results.get('rows', []): 
    for row in results.get('rows'): 
    writer.writerow(row) 
    print(''.join('%30s' % r for r in row)) 

else: 
    print ('No Rows Found') 

f.close() 

Answer 1

In [26]: import pandas as pd 

In [27]: import datetime 

In [28]: a = pd.read_csv('a.csv') 

In [29]: a 
Out[29]: 
columnA 
0  1 
1  2 

In [30]: a['Date'] = [datetime.date.today()]*len(a) 

In [31]: a 
Out[31]: 
columnA  Date 
0  1 2016-02-05 
1  2 2016-02-05 

In [32]: a.to_csv('adate.csv') 

一般：https://www.airpair.com/python/posts/top-mistakes-python-big-data-analytics