python中shift(1)_Pandas Shift函数的基础入门学习笔记

Pandas Shift函数基础

在使用Pandas的过程中，有时会遇到shift函数，今天就一起来彻底学习下。先来看看帮助文档是怎么说的：

>>> import pandas

>>> help(pandas.DataFrame.shift)

Help on function shift in module pandas.core.frame:

shift(self, periods=1, freq=None, axis=0)

Shift index by desired number of periods with an optional time freq

Parameters

----------

periods : int

Number of periods to move, can be positive or negative

freq : DateOffset, timedelta, or time rule string, optional

Increment to use from the tseries module or time rule (e.g. 'EOM').

See Notes.

axis : {0 or 'index', 1 or 'columns'}

Notes

-----

If freq is specified then the index values are shifted but the data

is not realigned. That is, use freq if you would like to extend the

index when shifting and preserve the original data.

Returns

-------

shif