How do you add a column in a DataFrame in Python?

This is a question of curiosity since it is my understanding that the following syntax.

>>> df = pd.DataFrame() id name. 0 a.m. 1 b. 2 c. 3 d. >>> df.tail(1) 4 d. Only removes the last row but does not add anything. To my understanding, it should have added an extra column (which would have been empty, since it was appended but I thought that Pandas should have created it).

But this syntax. >>> df = pd. It adds the new column but gives me the error message AttributeError: 'Series' object has no attribute 'getitemaxisiterator'. I am using Python 3.6 and pandas 0.19.

How do I add an empty column to a CSV file in Python?

I have a list of objects, and I'm using them to write a csv file.

I want to add an empty column in between the first two columns, but every time I do, it just adds a new row with that column and that row's first element.append(object)

With open('testfile.csv', 'wb') as f: writer = csv.writer(f) writer.writerows(data) And here's the CSV file: "Name","Gender","Height","Weight","ID". Maverick,Male,6'0",200,1. Grommet,Male,5'0",165,2. Zeus,Male,6'4",240,3. I would like the CSV file to look like this: "Name","Gender","Height","Weight","ID", "Something Empty". Maverick,Male,6'0",200,1,"Something Empty". Grommet,Male,5'0",165,2,"Something Empty". Zeus,Male,6'4",240,3,"Something Empty". I don't want to add something like a blank row above the "Name" column, because if I do that, it will be overwritten with the name. And I don't want to add a blank row before the "Gender" column, because then I won't be able to access the value of the Gender column.

You can't. You have to create a header row for the CSV file to work.