Pandas Concepts: Reference and Examples
Last updated:Table of Contents
Index
A Index
is just a Numpy array.
An Index
is used to locate elements in a Series or rows in a DataFrame.
import pandas as pd
i = pd.Index([0,1,2,3])
# Int64Index([0, 1, 2, 3], dtype='int64')
An Index may contain non-numeric elements
import pandas as pd
string_i = pd.Index(['a','b','c','d'])
string_i
#Index(['a', 'b', 'c', 'd'], dtype='object')
Series
A Series
is a data ndarray
plus an Index
.
import pandas as pd
i = pd.Index([0,1,2,3])
# Int64Index([0, 1, 2, 3], dtype='int64')
s = pd.Series([10,20,30,40],index=i)
# 0 10
# 1 20
# 2 30
# 3 40
# dtype: int64
Dataframe
A dataframe is a list of Series objects, where all Series have the same index.
Index vs Series
The Index is part of a Series.
Series = Index + Data array
Series vs Dataframe
A dataframe is a list of Series objects, where all Series have the same index.
You can turn a Series into a DataFrame (with a single column) by calling .toframe()
on the Series object.