[Python-bugs-list] [ python-Bugs-685011 ] calendar module overflow handling

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Bugs item #685011, was opened at 2003-02-11 19:34
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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=685011&group_id=5470

Category: Python Library
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Richard Jones (richard)
>Assigned to: Raymond Hettinger (rhettinger)
Summary: calendar module overflow handling

Initial Comment:
The calendar module has lost a significant area of functionality in 
Python 2.3  
- that of handling overflows in the tuples passed to timegm(). 
 
Python 2.2.2 (#1, Oct 28 2002, 16:39:08) 
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import time,calendar 
>>> time.gmtime(calendar.timegm((2003,1,30,0,0,0,0,0,0))) 
(2003, 1, 30, 0, 0, 0, 3, 30, 0) 
>>> time.gmtime(calendar.timegm((2003,2,30,0,0,0,0,0,0))) 
(2003, 3, 2, 0, 0, 0, 6, 61, 0) 
>>> 
 
Python 2.3a1 (#1, Feb  6 2003, 14:54:16) 
[GCC 2.96 20000731 (Red Hat Linux 7.1 2.96-98)] on linux2 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import time,calendar 
>>> time.gmtime(calendar.timegm((2003,1,30,0,0,0,0,0,0))) 
(2003, 1, 30, 0, 0, 0, 3, 30, 0) 
>>> time.gmtime(calendar.timegm((2003,2,30,0,0,0,0,0,0))) 
Traceback (most recent call last): 
  File "<stdin>", line 1, in ? 
  File "/usr/lib/python2.3/calendar.py", line 216, in timegm 
    days = datetime.date(year, month, day).toordinal() - _EPOCH_ORD 
ValueError: day is out of range for month 
>>> 
 
 
Is this functionality likely to be reinstated for 2.3's release? 
 

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>Comment By: Tim Peters (tim_one)
Date: 2003-02-11 19:54

Message:
Logged In: YES 
user_id=31435

Cute.  My best reading of the code is that you were relying 
on an undocumented accident.  The timegm code in 2.2 did 
do bounds-checking on the year and month, it looks like it 
was just too lazy to check the day.

Assigning to Raymond to teach him a lesson <wink>.  If you 
want to restore this accident, pass 1 instead of days to the 
datetime constructor, and restore the old

    days = days + day - 1

line after that returns.  It should still be lot faster than the 
2.2 code.


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