Pandas有条件的新列基于在其他数据框列中找到的期间

Question

I have a dataframe with file extensions. Some have periods in them I am trying to create a new column flagging which ones contain a period or not conditionally. If I wanted to just get the rows that contain a period I would just use: send_rec_file_url[send_rec_file_url['file_name'].str.contains('\\.')] .

How do I create a new column like below?

df
    file_name
0   png 
1   jpg
2   jpg
3   pdf
4   pdf
5   xlsx
6   docx.pdf
7   txt.scf
8   pdf
9   TXT.vbs
10  read_this.pdf 

Desired output:

df
    file_name      has_period
0   png            no
1   jpg            no
2   jpg            no
3   pdf            no
4   pdf            no
5   xlsx           no
6   docx.pdf       yes
7   txt.scf        yes
8   pdf            no
9   TXT.vbs        yes
10  read_this.pdf  yes

Answer 1

You need to use the mask to change the value of the column.

df['has_period'] = 'no'
df.loc[df['file_name'].str.contains('\.'), 'has_period'] = 'yes'

Output:

           file_name has_period
0             png         no
1             jpg         no
2             jpg         no
3             pdf         no
4             pdf         no
5            xlsx         no
6        docx.pdf        yes
7         txt.scf        yes
8             pdf         no
9         TXT.vbs        yes
10  read_this.pdf        yes

Answer 2

You can try:

df['has_period'] = ["Yes" if '.' in i else "No" for i in df['file_name']]

Output:

        file_name has_period
0             png         No
1             jpg         No
2             jpg         No
3             pdf         No
4             pdf         No
5            xlsx         No
6        docx.pdf        Yes
7         txt.scf        Yes
8             pdf         No
9         TXT.vbs        Yes
10  read_this.pdf        Yes

Note: pandas .str accessor is pretty slow, this solution should outperform .str accessor solutions.