DataFrame.shift

DataFrame.shift(periods=1, freq=None, axis=0, fill_value=)
使用可选的时间频率按所需的周期数移动索引。

Parameters

periods	要移动的周期数。可以是正也可以是负。
freq	偏移量
axis	0或index：行偏移；1或columns：列偏移
fill_value	用于新引入的缺失值的标量值，默认值取决于self的dtype。 - 对于数值数据：np.nan； - 对于日期时间：NaT； - 对于扩展数据：self.dtype.na_value

Example

import pandas as pd
df = pd.DataFrame({'site':['google', 'baidu', 'wiki', 'pandas'],
                    'age':[18, 39, 22, 45],
                    'price': [1.0, 2.0, 3.0, 4.0],
                    'color': ['red', 'black', None, 'red']}, index=['2021-01-01', '2021-01-02', '2021-01-03', '2021-01-04'])
df.shift(periods=2)
-------------------------------------------------------------------
            site    age        price    color
2021-01-01    NaN        NaN        NaN        NaN
2021-01-02    NaN        NaN        NaN        NaN
2021-01-03    google    18.0    1.0        red
2021-01-04    baidu    39.0    2.0        black

Example

import pandas as pd
df = pd.DataFrame({'site':['google', 'baidu', 'wiki', 'pandas'],
                    'age':[18, 39, 22, 45],
                    'price': [1.0, 2.0, 3.0, 4.0],
                    'color': ['red', 'black', None, 'red']}, index=['2021-01-01', '2021-01-02', '2021-01-03', '2021-01-04'])
df.shift(periods=1, axis='columns')
---------------------------------------------------------
            site    age        price    color
2021-01-01    NaN        google    18        1.0
2021-01-02    NaN        baidu    39        2.0
2021-01-03    NaN        wiki    22        3.0
2021-01-04    NaN        pandas    45        4.0

Example

import pandas as pd
df = pd.DataFrame({'site':['google', 'baidu', 'wiki', 'pandas'],
                    'age':[18, 39, 22, 45],
                    'price': [1.0, 2.0, 3.0, 4.0],
                    'color': ['red', 'black', None, 'red']}, index=['2021-01-01', '2021-01-02', '2021-01-03', '2021-01-04'])
df.shift(periods=1, fill_value=0)
--------------------------------------------------------------------
            site    age    price    color
2021-01-01    0        0    0.0        0
2021-01-02    google    18    1.0        red
2021-01-03    baidu    39    2.0        black
2021-01-04    wiki    22    3.0        None