Pandas version of rbind

Question

In R, you can combine two dataframes by sticking the columns of one onto the bottom of the columns of the other using rbind. In pandas, how do you accomplish the same thing? It

Answer 1

import pandas as pd 
import numpy as np

If you have a DataFrame like this:

array = np.random.randint( 0,10, size = (2,4) )
df = pd.DataFrame(array, columns = ['A','B', 'C', 'D'], \ 
                           index = ['10aa', '20bb'] )  ### some crazy indexes
df

      A  B  C  D
10aa  4  2  4  6
20bb  5  1  0  2

And you want add some NEW ROW which is a list (or another iterable object):

List = [i**3 for i in range(df.shape[1]) ]
List
[0, 1, 8, 27]

You should transform list to dictionary with keys equals columns in DataFrame with zip() function:

Dict = dict(  zip(df.columns, List)  )
Dict
{'A': 0, 'B': 1, 'C': 8, 'D': 27}

Than you can use append() method to add new dictionary:

df = df.append(Dict, ignore_index=True)
df
    A   B   C   D
0   7   5   5   4
1   5   8   4   1
2   0   1   8   27

N.B. the indexes are droped.

And yeah, it's not as simple as cbind() in R :(