Create a Pandas Dataframe by appending one row at a time


How do I create an empty DataFrame, then add rows, one by one?

I created an empty DataFrame:

df = pd.DataFrame(columns=('lib', 'qty1', 'qty2'))

Then I can add a new row at the end and fill a single field with:

df = df._set_value(index=len(df), col='qty1', value=10.0)

It works for only one field at a time. What is a better way to add new row to df?


You can use df.loc[i], where the row with index i will be what you specify it to be in the dataframe.

>>> import pandas as pd
>>> from numpy.random import randint

>>> df = pd.DataFrame(columns=[’lib’, ‘qty1’, ‘qty2’]) >>> for i in range(5): >>> df.loc[i] = [’name’ + str(i)] + list(randint(10, size=2))

>>> df lib qty1 qty2 0 name0 3 3 1 name1 2 4 2 name2 2 8 3 name3 2 1 4 name4 9 6

How do I expand the output display to see more columns of a Pandas DataFrame?

Difference between map, applymap and apply methods in Pandas