Conditional writing to xlsx

Question

Folks,

I'm currently working with a huge excel sheet, python 3.7.1 and pandas 0.23.4. My task is to write to cells based on conditional matching. Something like this:

val = lincoln@gmx.net
if val in Cell_3A:
    write something to Cell_3B

To make a complete example, let's say the following is my dataframe:

    Email               Protection
1   lincoln@gmail.net
2   obama@gmail.net
3   trump@gmail.net
4   franklin@gmail.net

I know want to write down that all of the emails are protected, except for the email in row 3. So the finished dataframe should look like this:

    Email               Protection
1   lincoln@gmail.net   on
2   obama@gmail.net     on
3   trump@gmail.net     off
4   franklin@gmail.net  on

How do I achieve this?

Answer 1

filter the Protection column where the email is not 'trump@gmail.net' and assign them 'on' and vice versa.

df.loc[df['Email']!='trump@gmail.net', 'Protection']='on'
df.loc[df['Email']=='trump@gmail.net', 'Protection']='off'

using np.where :

df['Protection'] = np.where((df['Email']!='trump@gmail.net'),'on','off')

or:

df['Protection'] = np.where((df['Email']=='trump@gmail.net'),'off','on')

Answer 2

Just another Solution around based on if and else condition:

DataFrame:

>>> df
                Email Protection
0   lincoln@gmail.net
1     obama@gmail.net
2     trump@gmail.net
3  franklin@gmail.net

Result:

>>> df['Protection'] = ['On' if x !="trump@gmail.net"  else 'Off' for x in df['Email']]
 # df['Protection'] = ['Off' if x =="trump@gmail.net"  else 'On' for x in df['Email']]
>>> df
                Email Protection
0   lincoln@gmail.net         On
1     obama@gmail.net         On
2     trump@gmail.net        Off
3  franklin@gmail.net         On