aoc-2022/venv/Lib/site-packages/pandas/_libs/tslibs/ccalendar.pyx

290 lines
6.8 KiB
Cython

# 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