mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-09-19 07:00:59 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

Issue #9151: Demo/classes/Dates.py does not work in 3.x Converted

Browse source 
descriptive comment into a docstring.  Cast attributes to int in
__init__.  Use __new__ instead of deleting attributes to
"uninitialize".
This commit is contained in:
Alexander Belopolsky 2010-07-03 22:05:41 +00:00
parent 2cf1585499
commit 401d856309
1 changed files with 45 additions and 46 deletions
Download patch file Download diff file Expand all files Collapse all files

91
Demo/classes/Dates.py
View file

@ -1,43 +1,45 @@
# Class Date supplies date objects that support date arithmetic. """
# Class Date supplies date objects that support date arithmetic.
# Date(month,day,year) returns a Date object. An instance prints as,
# e.g., 'Mon 16 Aug 1993'.
#
# Addition, subtraction, comparison operators, min, max, and sorting
# all work as expected for date objects: int+date or date+int returns
# the date `int' days from `date'; date+date raises an exception;
# date-int returns the date `int' days before `date'; date2-date1 returns
# an integer, the number of days from date1 to date2; int-date raises an
# exception; date1 < date2 is true iff date1 occurs before date2 (&
# similarly for other comparisons); min(date1,date2) is the earlier of
# the two dates and max(date1,date2) the later; and date objects can be
# used as dictionary keys.
#
# Date objects support one visible method, date.weekday(). This returns
# the day of the week the date falls on, as a string.
#
# Date objects also have 4 read-only data attributes:
# .month in 1..12
# .day in 1..31
# .year int or long int
# .ord the ordinal of the date relative to an arbitrary staring point
#
# The Dates module also supplies function today(), which returns the
# current date as a date object.
#
# Those entranced by calendar trivia will be disappointed, as no attempt
# has been made to accommodate the Julian (etc) system. On the other
# hand, at least this package knows that 2000 is a leap year but 2100
# isn't, and works fine for years with a hundred decimal digits <wink>.
# Tim Peters tim@ksr.com Date(month,day,year) returns a Date object. An instance prints as,
# not speaking for Kendall Square Research Corp e.g., 'Mon 16 Aug 1993'.
# Adapted to Python 1.1 (where some hacks to overcome coercion are unnecessary) Addition, subtraction, comparison operators, min, max, and sorting
# by Guido van Rossum all work as expected for date objects: int+date or date+int returns
the date `int' days from `date'; date+date raises an exception;
date-int returns the date `int' days before `date'; date2-date1 returns
an integer, the number of days from date1 to date2; int-date raises an
exception; date1 < date2 is true iff date1 occurs before date2 (&
similarly for other comparisons); min(date1,date2) is the earlier of
the two dates and max(date1,date2) the later; and date objects can be
used as dictionary keys.
# Note that as of Python 2.3, a datetime module is included in the stardard Date objects support one visible method, date.weekday(). This returns
# library. the day of the week the date falls on, as a string.
Date objects also have 4 read-only data attributes:
.month in 1..12
.day in 1..31
.year int or long int
.ord the ordinal of the date relative to an arbitrary staring point
The Dates module also supplies function today(), which returns the
current date as a date object.
Those entranced by calendar trivia will be disappointed, as no attempt
has been made to accommodate the Julian (etc) system. On the other
hand, at least this package knows that 2000 is a leap year but 2100
isn't, and works fine for years with a hundred decimal digits <wink>.
Tim Peters tim@ksr.com
not speaking for Kendall Square Research Corp
Adapted to Python 1.1 (where some hacks to overcome coercion are unnecessary)
by Guido van Rossum
Note that as of Python 2.3, a datetime module is included in the stardard
library.
"""
import functools import functools
@ -86,8 +88,9 @@ def _num2date(n): # return date with ordinal n
if not isinstance(n, int): if not isinstance(n, int):
raise TypeError('argument must be integer: %r' % type(n)) raise TypeError('argument must be integer: %r' % type(n))
ans = Date(1,1,1) # arguments irrelevant; just getting a Date obj # Get uninitialized Date object. This is necesary because once
del ans.ord, ans.month, ans.day, ans.year # un-initialize it # attributes are set, they cannot be changed.
ans = Date.__new__(Date)
ans.ord = n ans.ord = n
n400 = (n-1)//_DI400Y # # of 400-year blocks preceding n400 = (n-1)//_DI400Y # # of 400-year blocks preceding
@ -97,11 +100,7 @@ def _num2date(n): # return date with ordinal n
if dby >= n: if dby >= n:
more = more - 1 more = more - 1
dby = dby - _days_in_year(more) dby = dby - _days_in_year(more)
year, n = year + more, int(n - dby) year, n = year + more, n - dby
try: year = int(year) # chop to int, if it fits
except (ValueError, OverflowError): pass
month = min(n//29 + 1, 12) month = min(n//29 + 1, 12)
dbm = _days_before_month(month, year) dbm = _days_before_month(month, year)
if dbm >= n: if dbm >= n:
@ -112,7 +111,7 @@ def _num2date(n): # return date with ordinal n
return ans return ans
def _num2day(n): # return weekday name of day with ordinal n def _num2day(n): # return weekday name of day with ordinal n
return _DAY_NAMES[ int(n % 7) ] return _DAY_NAMES[n % 7]
@functools.total_ordering @functools.total_ordering
class Date: class Date:
@ -122,7 +121,7 @@ class Date:
dim = _days_in_month(month, year) dim = _days_in_month(month, year)
if not 1 <= day <= dim: if not 1 <= day <= dim:
raise ValueError('day must be in 1..%r: %r' % (dim, day)) raise ValueError('day must be in 1..%r: %r' % (dim, day))
self.month, self.day, self.year = month, day, year self.month, self.day, self.year = map(int, (month, day, year))
self.ord = _date2num(self) self.ord = _date2num(self)
# don't allow setting existing attributes # don't allow setting existing attributes