Insert a new column in existing DataFrame
A pandas dataframe is implemented as an ordered dict of columns. In this article, you will get to know how to add a new column to an existing data frame. So first let's create a data frame with values.
Using  accessor
Here, when you use the  to pandas DataFrame is quietly performing an outer join or outer merge using the index of the left hand dataframe and the index of the right hand series. df['column'] = series.
Using insert() method
You can inset a column to pandas DataFrmae at a specified index using insert() method.
Here you can see the column 'Age' inserted at the index position of 1 using insert() method.
Using assign() method
Pandas DataFrame has an assign() function that allows you to create a new dataframe with new column added to the old dataframe.