Python | Панды dataframe.shift ()
Python - отличный язык для анализа данных, в первую очередь из-за фантастической экосистемы пакетов Python, ориентированных на данные. Pandas - один из таких пакетов, который значительно упрощает импорт и анализ данных.
Pandas dataframe.shift() function Shift index by desired number of periods with an optional time freq. This function takes a scalar parameter called period, which represents the number of shifts to be made over the desired axis. This function is very helpful when dealing with time-series data.
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
Example #1: Use shift() function to shift the index axis by 2 periods in a time-series data
# importing pandas as pdimport 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 dataframedf = 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 dataframedf |
Lets use the dataframe.shift() function to shift the index axis by 2 periods in positive direction
# shift index axis by two periods in positive direction# axis = 0 is set by defaultdf.shift(2, axis = 0) |
Lets shift the index axis in negative direction by some periods
# shift index axis by two periods in negative direction# axis = 0 is set by defaultdf.shift(-2, axis = 0) |
Выход :
Example #2: Use shift() function to shift the column axis by 2 periods in a time-series data
# importing pandas as pdimport 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 dataframedf = 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 dataframedf |
Lets use the dataframe.shift() function to shift the column axis by 2 periods in positive direction
# shift column axis by two periods in positive directiondf.shift(2, axis = 1) |
Lets shift the column axis in negative direction by some periods
# shift column axis by two periods in negative directiondf.shift(-2, axis = 0) |
Выход :
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