# 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
|
