# cython: boundscheck=False """ Cython implementations of functions resembling the stdlib calendar module """ cimport cython from numpy cimport ( int32_t, int64_t, ) # ---------------------------------------------------------------------- # Constants # Slightly more performant cython lookups than a 2D table # The first 12 entries correspond to month lengths for non-leap years. # The remaining 12 entries give month lengths for leap years cdef int32_t* days_per_month_array = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] cdef int* sakamoto_arr = [0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4] # The first 13 entries give the month days elapsed as of the first of month N # (or the total number of days in the year for N=13) in non-leap years. # The remaining 13 entries give the days elapsed in leap years. cdef int32_t* month_offset = [ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366] # Canonical location for other modules to find name constants MONTHS = ['JAN', 'FEB', 'MAR', 'APR', 'MAY', 'JUN', 'JUL', 'AUG', 'SEP', 'OCT', 'NOV', 'DEC'] # The first blank line is consistent with calendar.month_name in the calendar # standard library MONTHS_FULL = ['', 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'] MONTH_NUMBERS = {name: num for num, name in enumerate(MONTHS)} cdef dict c_MONTH_NUMBERS = MONTH_NUMBERS MONTH_ALIASES = {(num + 1): name for num, name in enumerate(MONTHS)} MONTH_TO_CAL_NUM = {name: num + 1 for num, name in enumerate(MONTHS)} DAYS = ['MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT', 'SUN'] DAYS_FULL = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'] int_to_weekday = {num: name for num, name in enumerate(DAYS)} weekday_to_int = {int_to_weekday[key]: key for key in int_to_weekday} # ---------------------------------------------------------------------- @cython.wraparound(False) @cython.boundscheck(False) cpdef int32_t get_days_in_month(int year, Py_ssize_t month) nogil: """ Return the number of days in the given month of the given year. Parameters ---------- year : int month : int Returns ------- days_in_month : int Notes ----- Assumes that the arguments are valid. Passing a month not between 1 and 12 risks a segfault. """ return days_per_month_array[12 * is_leapyear(year) + month - 1] @cython.wraparound(False) @cython.boundscheck(False) @cython.cdivision cdef int dayofweek(int y, int m, int d) nogil: """ Find the day of week for the date described by the Y/M/D triple y, m, d using Sakamoto's method, from wikipedia. 0 represents Monday. See [1]_. Parameters ---------- y : int m : int d : int Returns ------- weekday : int Notes ----- Assumes that y, m, d, represents a valid date. See Also -------- [1] https://docs.python.org/3/library/calendar.html#calendar.weekday [2] https://en.wikipedia.org/wiki/\ Determination_of_the_day_of_the_week#Sakamoto.27s_methods """ cdef: int day y -= m < 3 day = (y + y / 4 - y / 100 + y / 400 + sakamoto_arr[m - 1] + d) % 7 # convert to python day return (day + 6) % 7 cdef bint is_leapyear(int64_t year) nogil: """ Returns 1 if the given year is a leap year, 0 otherwise. Parameters ---------- year : int Returns ------- is_leap : bool """ return ((year & 0x3) == 0 and # year % 4 == 0 ((year % 100) != 0 or (year % 400) == 0)) @cython.wraparound(False) @cython.boundscheck(False) cpdef int32_t get_week_of_year(int year, int month, int day) nogil: """ Return the ordinal week-of-year for the given day. Parameters ---------- year : int month : int day : int Returns ------- week_of_year : int32_t Notes ----- Assumes the inputs describe a valid date. """ return get_iso_calendar(year, month, day)[1] @cython.wraparound(False) @cython.boundscheck(False) cpdef iso_calendar_t get_iso_calendar(int year, int month, int day) nogil: """ Return the year, week, and day of year corresponding to ISO 8601 Parameters ---------- year : int month : int day : int Returns ------- year : int32_t week : int32_t day : int32_t Notes ----- Assumes the inputs describe a valid date. """ cdef: int32_t doy, dow int32_t iso_year, iso_week doy = get_day_of_year(year, month, day) dow = dayofweek(year, month, day) # estimate iso_week = (doy - 1) - dow + 3 if iso_week >= 0: iso_week = iso_week // 7 + 1 # verify if iso_week < 0: if (iso_week > -2) or (iso_week == -2 and is_leapyear(year - 1)): iso_week = 53 else: iso_week = 52 elif iso_week == 53: if 31 - day + dow < 3: iso_week = 1 iso_year = year if iso_week == 1 and month == 12: iso_year += 1 elif iso_week >= 52 and month == 1: iso_year -= 1 return iso_year, iso_week, dow + 1 @cython.wraparound(False) @cython.boundscheck(False) cpdef int32_t get_day_of_year(int year, int month, int day) nogil: """ Return the ordinal day-of-year for the given day. Parameters ---------- year : int month : int day : int Returns ------- day_of_year : int32_t Notes ----- Assumes the inputs describe a valid date. """ cdef: bint isleap int32_t mo_off int day_of_year isleap = is_leapyear(year) mo_off = month_offset[isleap * 13 + month - 1] day_of_year = mo_off + day return day_of_year # --------------------------------------------------------------------- # Business Helpers cpdef int get_lastbday(int year, int month) nogil: """ Find the last day of the month that is a business day. Parameters ---------- year : int month : int Returns ------- last_bday : int """ cdef: int wkday, days_in_month wkday = dayofweek(year, month, 1) days_in_month = get_days_in_month(year, month) return days_in_month - max(((wkday + days_in_month - 1) % 7) - 4, 0) cpdef int get_firstbday(int year, int month) nogil: """ Find the first day of the month that is a business day. Parameters ---------- year : int month : int Returns ------- first_bday : int """ cdef: int first, wkday wkday = dayofweek(year, month, 1) first = 1 if wkday == 5: # on Saturday first = 3 elif wkday == 6: # on Sunday first = 2 return first