Python Pandas dataframe.shift()用法及代碼示例

Python是進行數據分析的一種出色語言，主要是因為以數據為中心的python軟件包具有奇妙的生態係統。 Pandas是其中的一種，使導入和分析數據更加容易。

Pandas dataframe.shift()函數根據需要的周期數移動索引，並帶有可選的時間頻率。該函數采用稱為周期的標量參數，該參數表示要在所需軸上進行的平移次數。處理時間序列數據時，此函數非常有用。

用法：DataFrame.shift(periods=1, freq=None, axis=0)

參數:

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’}

返回：shifted：DataFrame

範例1：采用shift()在時間序列數據中將索引軸移動2個周期的函數

# 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

讓我們使用dataframe.shift()使索引軸向正方向移動2個周期的函數

# shift index axis by two periods in positive direction 
# axis = 0 is set by default 
df.shift(2, axis = 0)

讓索引軸在負方向上移動一段時間

# shift index axis by two periods in negative direction 
# axis = 0 is set by default 
df.shift(-2, axis = 0)

輸出：

範例2：采用shift()用於在時間序列數據中將列軸移動2個周期

# 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

讓我們使用dataframe.shift()沿正方向將列軸移動2個周期的函數

# shift column axis by two periods in positive direction 
df.shift(2, axis = 1)

讓列軸在負方向上移動一段時間

# shift column axis by two periods in negative direction 
df.shift(-2, axis = 0)

輸出：

相關用法

注：本文由純淨天空篩選整理自Shubham__Ranjan大神的英文原創作品 Python | Pandas dataframe.shift()。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。