Is there a way that I can add column with certain value while reading excel file using python pandas?
Now I have two steps, but I need to do it more than 30 files so I want to find elegant way to do it!
1) df_2007 = pd.read_excel('may2007_dl.xls')
2) df_2007['year'] = 2007
Thanks.
There's nothing wrong with your code. But if you'd like to do it in one line you can use assign, which assigns new columns to a DataFrame and returns a new object (a copy) with all the original columns in addition to the new ones.
df_2007 = pd.read_excel('may2007_dl.xls').assign(y=2007)
Demonstration:
In [68]: pd.read_csv('/tmp/test.csv')
Out[68]:
Unnamed: 0 one two
0 a 1.0 1.0
1 b 2.0 2.0
2 c 3.0 3.0
3 d NaN 4.0
In [69]: pd.read_csv('/tmp/test.csv').assign(a=2007)
Out[69]:
Unnamed: 0 one two a
0 a 1.0 1.0 2007
1 b 2.0 2.0 2007
2 c 3.0 3.0 2007
3 d NaN 4.0 2007
