What is size-mutable as per Python's pandas DataFrame class?

Question:

What does size-mutable mean, in this context?

“Two-dimensional size-mutable, potentially heterogeneous tabular data
structure with labeled axes (rows and columns). Arithmetic operations
align on both row and column labels. Can be thought of as a dict-like
container for Series objects. The primary pandas data structure”

from: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html

I presume it means the size is mutable–the size can be changed. Is this correct?

Asked By: ja_him

||

Answers:

You are right. Size mutable refers that elements can be appended or deleted/pop-ed from a DataFrame. On the contrary a Series is Size immutable, which means once a Series object is created operations such as appending/deleting which would change the size of the object are not allowed.

Answered By: Sandeep
>>> s
a    4.0
b    4.0
c    8.0
d    9.0
f    NaN
dtype: float64

>>> s.shape
(5,)

>>> s.drop('f',inplace=True)

>>> s
a    4.0
b    4.0
c    8.0
d    9.0
dtype: float64

>>> s.size
4

>>> s['f']=9

>>> s
a    4.0
b    4.0
c    8.0
d    9.0
f    9.0
dtype: float64

>>> s['g']=200

>>> s.size
6

Please go through the above Python commands that imply that Pandas Series are also size mutable.
The size of given series is initially 5.
Then I delete one element s.drop('f',inplace=True), so the size of the Series will be 4.
Then I again assign a new variable s['f']=9 and s['g']=200, then the size of the Series is 6 now.

Answered By: Sheetal