pandas Appending to DataFrame Appending a new row to DataFrame
Example
In [1]: import pandas as pd
In [2]: df = pd.DataFrame(columns = ['A', 'B', 'C'])
In [3]: df
Out[3]:
Empty DataFrame
Columns: [A, B, C]
Index: []
Appending a row by a single column value:
In [4]: df.loc[0, 'A'] = 1
In [5]: df
Out[5]:
A B C
0 1 NaN NaN
Appending a row, given list of values:
In [6]: df.loc[1] = [2, 3, 4]
In [7]: df
Out[7]:
A B C
0 1 NaN NaN
1 2 3 4
Appending a row given a dictionary:
In [8]: df.loc[2] = {'A': 3, 'C': 9, 'B': 9}
In [9]: df
Out[9]:
A B C
0 1 NaN NaN
1 2 3 4
2 3 9 9
The first input in .loc[] is the index. If you use an existing index, you will overwrite the values in that row:
In [17]: df.loc[1] = [5, 6, 7]
In [18]: df
Out[18]:
A B C
0 1 NaN NaN
1 5 6 7
2 3 9 9
In [19]: df.loc[0, 'B'] = 8
In [20]: df
Out[20]:
A B C
0 1 8 NaN
1 5 6 7
2 3 9 9
