Python|熊猫 dataframe.shift()
Python是一种用于进行数据分析的出色语言,主要是因为以数据为中心的Python包的奇妙生态系统。 Pandas就是其中之一,它使导入和分析数据变得更加容易。
Pandas dataframe.shift()函数将索引按所需的周期数和可选的时间频率移动。此函数采用一个称为period的标量参数,它表示要在所需轴上进行的移动次数。此函数在处理时间序列数据时非常有用。
Syntax:DataFrame.shift(periods=1, freq=None, axis=0)
Parameters :
periods : 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’}
Return : shifted : DataFrame
示例 #1:使用 shift()函数将时间序列数据中的索引轴移动 2 个周期
Python3
# importing pandas as pd
import pandas as pd
# Creating row index values for our data frame
# We have taken time frequency to be of 12 hours interval
# We are generating five index value using "period = 5" parameter
ind = pd.date_range('01 / 01 / 2000', periods = 5, freq ='12H')
# Creating a dataframe with 4 columns
# using "ind" as the index for our dataframe
df = pd.DataFrame({"A":[1, 2, 3, 4, 5],
"B":[10, 20, 30, 40, 50],
"C":[11, 22, 33, 44, 55],
"D":[12, 24, 51, 36, 2]},
index = ind)
# Print the dataframe
df
Python3
# shift index axis by two periods in positive direction
# axis = 0 is set by default
df.shift(2, axis = 0)
Python3
# shift index axis by two periods in negative direction
# axis = 0 is set by default
df.shift(-2, axis = 0)
Python3
# importing pandas as pd
import pandas as pd
# Creating row index values for our data frame
# We have taken time frequency to be of 12 hours interval
# We are generating five index value using "period = 5" parameter
ind = pd.date_range('01 / 01 / 2000', periods = 5, freq ='12H')
# Creating a dataframe with 4 columns
# using "ind" as the index for our dataframe
df = pd.DataFrame({"A":[1, 2, 3, 4, 5],
"B":[10, 20, 30, 40, 50],
"C":[11, 22, 33, 44, 55],
"D":[12, 24, 51, 36, 2]},
index = ind)
# Print the dataframe
df
Python3
# shift column axis by two periods in positive direction
df.shift(2, axis = 1)
Python3
# shift column axis by two periods in negative direction
df.shift(-2, axis = 1)
输出:
让我们使用 dataframe.shift()函数将索引轴在正方向上移动 2 个周期
Python3
# shift index axis by two periods in positive direction
# axis = 0 is set by default
df.shift(2, axis = 0)
输出:
让我们将索引轴向负方向移动一些周期
Python3
# shift index axis by two periods in negative direction
# axis = 0 is set by default
df.shift(-2, axis = 0)
输出 :
示例 #2:使用 shift()函数将时间序列数据中的列轴移动 2 个周期
Python3
# importing pandas as pd
import pandas as pd
# Creating row index values for our data frame
# We have taken time frequency to be of 12 hours interval
# We are generating five index value using "period = 5" parameter
ind = pd.date_range('01 / 01 / 2000', periods = 5, freq ='12H')
# Creating a dataframe with 4 columns
# using "ind" as the index for our dataframe
df = pd.DataFrame({"A":[1, 2, 3, 4, 5],
"B":[10, 20, 30, 40, 50],
"C":[11, 22, 33, 44, 55],
"D":[12, 24, 51, 36, 2]},
index = ind)
# Print the dataframe
df
让我们使用 dataframe.shift()函数将列轴沿正方向移动 2 个周期
Python3
# shift column axis by two periods in positive direction
df.shift(2, axis = 1)
让我们将列轴向负方向移动一些周期
Python3
# shift column axis by two periods in negative direction
df.shift(-2, axis = 1)
输出 :