python append inplace code example

Example 1: python append vs extend

my_list = [23, 11, 42, 24523]

# append will add it as if you're adding a new list to it
my_list.append([34523, 76979])
print(my_list)

# extend will go over each item in the new source list and add each
# element as part of the target list (my_list)
my_list.extend([12, 99])
print(my_list)

""" 
Output:
[23, 11, 42, 24523, [34523, 76979]]
[23, 11, 42, 24523, [34523, 76979], 12, 99]
"""

Example 2: appending dataframes pandas

>>> df = pd.DataFrame([[1, 2], [3, 4]], columns=list('AB'))
>>> df
   A  B
0  1  2
1  3  4
>>> df2 = pd.DataFrame([[5, 6], [7, 8]], columns=list('AB'))
>>> df.append(df2)
   A  B
0  1  2
1  3  4
0  5  6
1  7  8