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Method argpartition
NumPy Random Generator4 topics
Method choiceMethod dotMethod finfoMethod histogramMethod iinfoMethod maxMethod meanMethod placeMethod rootsMethod seedMethod uniformMethod viewMethod zerosMethod sumObject busdaycalendarMethod is_busdayProperty dtypeMethod uniqueMethod loadtxtMethod vsplitMethod fliplrMethod setdiff1dMethod msortMethod argsortMethod lexsortMethod aroundMethod nanmaxMethod nanminMethod nanargmaxMethod nanargminMethod argmaxMethod argminProperty itemsizeMethod spacingMethod fixMethod ceilMethod diffProperty flatProperty realProperty baseMethod flipMethod deleteMethod amaxMethod aminMethod logical_xorMethod logical_orMethod logical_notMethod logical_andMethod logaddexpMethod logaddexp2Method logspaceMethod not_equalMethod equalMethod greater_equalMethod lessMethod less_equalMethod remainderMethod modMethod emptyMethod greaterMethod isfiniteMethod busday_countMethod repeatMethod varMethod random_sampleMethod randomMethod signMethod stdMethod absoluteMethod absMethod sortMethod randintMethod isrealMethod linspaceMethod gradientMethod allMethod sampleProperty TProperty imagMethod covMethod insertMethod logMethod log1pMethod exp2Method expm1Method expMethod arccosMethod cosMethod arcsinMethod sinMethod tanMethod fromiterMethod trim_zerosMethod diagflatMethod savetxtMethod count_nonzeroProperty sizeProperty shapeMethod reshapeMethod resizeMethod triuMethod trilMethod eyeMethod arangeMethod fill_diagonalMethod tileMethod saveMethod transposeMethod swapaxesMethod meshgridProperty mgridMethod rot90Method log2Method radiansMethod deg2radMethod rad2degMethod degreesMethod log10Method appendMethod cumprodProperty nbytesMethod tostringProperty dataMethod modfMethod fmodMethod tolistMethod datetime_as_stringMethod datetime_dataMethod array_splitMethod itemsetMethod floorMethod put_along_axisMethod cumsumMethod bincountMethod putMethod putmaskMethod takeMethod hypotMethod sqrtMethod squareMethod floor_divideMethod triMethod signbitMethod flattenMethod ravelMethod rollMethod isrealobjMethod diagMethod diagonalMethod quantileMethod onesMethod iscomplexobjMethod iscomplexMethod isscalarMethod divmodMethod isnatMethod percentileMethod isnanMethod divideMethod addMethod reciprocalMethod positiveMethod subtractMethod medianMethod isneginfMethod isposinfMethod float_powerMethod powerMethod negativeMethod maximumMethod averageMethod isinfMethod multiplyMethod busday_offsetMethod identityMethod interpMethod squeezeMethod get_printoptionsMethod savez_compressedMethod savezMethod loadMethod asfarrayMethod clipMethod arrayMethod array_equivMethod array_equalMethod frombufferMethod set_string_functionMethod matmulMethod genfromtxtMethod fromfunctionMethod asscalarMethod searchsortedMethod full_likeMethod fullMethod shares_memoryMethod ptpMethod digitizeMethod argwhereMethod geomspaceMethod zeros_likeMethod fabsMethod flatnonzeroMethod vstackMethod dstackMethod fromstringMethod tobytesMethod expand_dimsMethod ranfMethod arctanMethod itemMethod extractMethod compressMethod chooseMethod asarrayMethod asmatrixMethod allcloseMethod iscloseMethod anyMethod corrcoefMethod truncMethod prodMethod crossMethod true_divideMethod hsplitMethod splitMethod rintMethod ediff1dMethod lcmMethod gcdMethod cbrtMethod flipudProperty ndimMethod array2stringMethod set_printoptionsMethod whereMethod hstack
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chevron_left Documentation
Method argpartition
NumPy Random Generator4 topics
Method choiceMethod dotMethod finfoMethod histogramMethod iinfoMethod maxMethod meanMethod placeMethod rootsMethod seedMethod uniformMethod viewMethod zerosMethod sumObject busdaycalendarMethod is_busdayProperty dtypeMethod uniqueMethod loadtxtMethod vsplitMethod fliplrMethod setdiff1dMethod msortMethod argsortMethod lexsortMethod aroundMethod nanmaxMethod nanminMethod nanargmaxMethod nanargminMethod argmaxMethod argminProperty itemsizeMethod spacingMethod fixMethod ceilMethod diffProperty flatProperty realProperty baseMethod flipMethod deleteMethod amaxMethod aminMethod logical_xorMethod logical_orMethod logical_notMethod logical_andMethod logaddexpMethod logaddexp2Method logspaceMethod not_equalMethod equalMethod greater_equalMethod lessMethod less_equalMethod remainderMethod modMethod emptyMethod greaterMethod isfiniteMethod busday_countMethod repeatMethod varMethod random_sampleMethod randomMethod signMethod stdMethod absoluteMethod absMethod sortMethod randintMethod isrealMethod linspaceMethod gradientMethod allMethod sampleProperty TProperty imagMethod covMethod insertMethod logMethod log1pMethod exp2Method expm1Method expMethod arccosMethod cosMethod arcsinMethod sinMethod tanMethod fromiterMethod trim_zerosMethod diagflatMethod savetxtMethod count_nonzeroProperty sizeProperty shapeMethod reshapeMethod resizeMethod triuMethod trilMethod eyeMethod arangeMethod fill_diagonalMethod tileMethod saveMethod transposeMethod swapaxesMethod meshgridProperty mgridMethod rot90Method log2Method radiansMethod deg2radMethod rad2degMethod degreesMethod log10Method appendMethod cumprodProperty nbytesMethod tostringProperty dataMethod modfMethod fmodMethod tolistMethod datetime_as_stringMethod datetime_dataMethod array_splitMethod itemsetMethod floorMethod put_along_axisMethod cumsumMethod bincountMethod putMethod putmaskMethod takeMethod hypotMethod sqrtMethod squareMethod floor_divideMethod triMethod signbitMethod flattenMethod ravelMethod rollMethod isrealobjMethod diagMethod diagonalMethod quantileMethod onesMethod iscomplexobjMethod iscomplexMethod isscalarMethod divmodMethod isnatMethod percentileMethod isnanMethod divideMethod addMethod reciprocalMethod positiveMethod subtractMethod medianMethod isneginfMethod isposinfMethod float_powerMethod powerMethod negativeMethod maximumMethod averageMethod isinfMethod multiplyMethod busday_offsetMethod identityMethod interpMethod squeezeMethod get_printoptionsMethod savez_compressedMethod savezMethod loadMethod asfarrayMethod clipMethod arrayMethod array_equivMethod array_equalMethod frombufferMethod set_string_functionMethod matmulMethod genfromtxtMethod fromfunctionMethod asscalarMethod searchsortedMethod full_likeMethod fullMethod shares_memoryMethod ptpMethod digitizeMethod argwhereMethod geomspaceMethod zeros_likeMethod fabsMethod flatnonzeroMethod vstackMethod dstackMethod fromstringMethod tobytesMethod expand_dimsMethod ranfMethod arctanMethod itemMethod extractMethod compressMethod chooseMethod asarrayMethod asmatrixMethod allcloseMethod iscloseMethod anyMethod corrcoefMethod truncMethod prodMethod crossMethod true_divideMethod hsplitMethod splitMethod rintMethod ediff1dMethod lcmMethod gcdMethod cbrtMethod flipudProperty ndimMethod array2stringMethod set_printoptionsMethod whereMethod hstack
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NumPy | busday_offset method

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schedule Mar 9, 2022
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NumPy's busday_offset(~) method shifts the provided datetimes by a specific offset in valid days. Note that busday stands for business day, but we can specify what a "business" day is via the parameters.

Parameters

1. dates | array-like of datetime

The input datetimes. Datetimes are essentially strings formatted like so:

"2020-05-25"

2. offsets | array-like of int

The number of days to offset by.

3. roll | string | optional

How to deal with invalid dates prior to offsetting. The allowed values are as follows:

Value

Description

raise

Throw an error.

nat

Return a NaT (i.e. not-a-time)

forward

Return the first valid date after this date

following

Return the first valid date after this date

backward

Return the last valid date before the this date

preceding

Return the last valid date before the this date

modifiedfollowing

If the first valid date after this date falls in the same month as this date, then return this date. Otherwise, return the last valid date before this date.

modifiedpreceding

If the last valid date before this date falls in the same month as this date, then return this date. Otherwise, return the first valid date after the this date.

By default, roll="raise". Look at the examples below for clarification.

3. weekmask | string or array-like of boolean | optional

The days of the week that are considered to be valid. You could either specify a string of length 7 with 0s representing invalid and 1s representing valid weekdays, from Monday to Sunday. For instance, "1111100" would mean that weekends (Saturday and Sunday) would be invalid dates. Also, instead of typing in binaries, you could also use three-character abbreviations like:

Mon Tue Wed Thu Fri Sat Sun

For instance, "Mon Wed Fri" would mean that only Mondays, Wednesdays and Fridays are valid dates, and all other weekdays are invalid.

Alternatively, you could provide an array of booleans of size 7, where True means that that corresponding weekday is valid, and False otherwise. For instance, [True,True,True,True,True,False,False] would again mean that weekends would be invalid dates.

By default, weekmask="1111100", that is, valid weekdays are from Monday to Friday (both inclusive).

4. holidays | array-like of datetime | optional

An array of datetimes that are deemed as invalid dates.

5. busdaycal | busdaycalender | optional

An busdaycalender object that specifies which dates are deemed as valid dates. If this parameter is provided, then you should not specify parameters weekmask and holidays.

6. out | Numpy array | optional

We can store the result in out, which saves memory space as a new Array is not created.

Return value

If a datetime is provided for begindates and enddates, then a single integer is returned. A Numpy array of integers that represent count of the dates that fall between the specified range.

Examples

Roll parameter

raise

Here we get an error because the date 2020-11-22 falls on a Sunday:

dates = ["2020-11-22", "2020-11-25", "2020-11-27"]
np.busday_offset(dates, 2)
ValueError: Non-business day date in busday_offset

nat

dates = ["2020-11-22", "2020-11-25", "2020-11-27"]
np.busday_offset(dates, 2, roll="nat")
array([ 'NaT', '2020-11-27', '2020-12-01'], dtype='datetime64[D]')

forward

dates = ["2020-11-22", "2020-11-25", "2020-11-27"]
np.busday_offset(dates, 2, roll="forward")
array(['2020-11-25', '2020-11-27', '2020-12-01'], dtype='datetime64[D]')

As we've said, the first date 2020-11-22 is invalid since it falls on a Sunday. The roll="forward" parameter means that the first valid date after this date is returned, which in this case, is 2020-11-23 (a Monday). Next, the offset of 2 is applied to give us 2020-11-25.

backward

dates = ["2020-11-22", "2020-11-25", "2020-11-27"]
np.busday_offset(dates, 2, roll="backward")
array(['2020-11-24', '2020-11-27', '2020-12-01'], dtype='datetime64[D]')

Again, the first date 2020-11-22 is invalid since it falls on a Sunday. The roll="backward" parameter means that the last valid date before this date is returned, which in this case, is 2020-11-20 (a Friday). Next, the offset of 2 valid days is applied, which entails completely skipping the invalid weekends (i.e. 21st and 22nd), and then applying the 2 days offset to give us 2020-11-24.

modifiedfollowing

dates = ["2020-05-30"]
np.busday_offset(dates, 2, roll="modifiedfollowing")
array(['2020-06-02'], dtype='datetime64[D]')

Here, 2020-05-30 is a Saturday, which is invalid. The roll="modifiedfollowing" parameter looks for the first valid date after this date, which is 2020-06-01 (Monday). Since we'e crossed over to the subsequent month, modifiedfollowing requires that we go to the last valid date before 2020-05-30, which is 2020-05-29 (Friday). We then perform the offsetting; we shift by 2 valid days (ignoring all invalid days), which would ultimately give us 2020-06-02!

modifiedpreceding

The section here will be omitted here for brevity, but this is essentially just the reverse of modifiedfollowing.

NOTE

To demonstrate how the other parameters work, we will use NumPy's is_busday(~) method instead.

Specifying a weekmask

np.is_busday(["2020-12-25", "2020-12-26", "2020-12-27"], "1111110")
array([ True, True, False])

Here, we're setting Sunday as an invalid date - if you check your calendar, you'll see that "2020-12-27" is a Sunday, so this is why we get a False for that entry.

Specifying holidays

Instead of specifying invalid dates, we can also specify just the valid dates and make all other dates invalid:

holidays = ["2020-12-25"]
np.is_busday(["2020-12-25", "2020-12-26", "2020-12-27"], "1111111", holidays)
array([False, True, True])

Here, False is returned for 2020-12-25 since we specified that date as a holiday, and holidays are considered to be invalid dates.

Specifying a valid date

Instead of specifying invalid dates, we can also specify just the valid dates and make all other dates invalid:

bdc = np.busdaycalendar(weekmask="1111111", holidays=["2020-12-26"])
np.is_busday(["2020-12-25", "2020-12-26", "2020-12-27"], busdaycal=bdc)
array([ True, False, True])

Here, busdaycalendar object specifies what dates are considered to be valid. It may be confusing here but the holidays used in the constructor of busdaycalendar is a list of valid datetimes.

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Published by Isshin Inada
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