Pandas Brain Teasers/

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Insert Columns into a Pandas DataFrame

Insert Columns into a Pandas DataFrame

Let's find out how to add a column to a pandas DataFrame.

We'll cover the following...

Try it yourself

Try executing the code below to see the result.

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import pandas as pd
df = pd.DataFrame([
  ['Sterling', 83.4],
  ['Cheryl', 97.2],
  ['Lana', 13.2],
], columns=['name', 'sum'])
df.late_fee = 3.5
print(df)

Explanation

Where did the late_fee column go? Python’s objects are very dynamic. We can add attributes to most of them as we please.

In [1]: class Point:
...: def __init__(self, x, y):
...: self.x, self.y = x, y
In [2]: p = Point(1, 2)
In [3]: p.x, p.y
Out[3]: (1, 2)
In [4]: p.z = 3
In [5]: p.z
Out[5]:
...