cpython/Lib/calendar.py
Raymond Hettinger 9ecf9ce161 Patches #626105:
Replaces the _center function in the calendar
module with the center method for strings.

For situations with uneven padding, the behavior is
slightly different in that the center method puts the
extra space on the right instead of the left.
2002-10-22 05:15:17 +00:00

231 lines
7.6 KiB
Python

"""Calendar printing functions
Note when comparing these calendars to the ones printed by cal(1): By
default, these calendars have Monday as the first day of the week, and
Sunday as the last (the European convention). Use setfirstweekday() to
set the first day of the week (0=Monday, 6=Sunday)."""
# Revision 2: uses functions from built-in time module
# Import functions and variables from time module
from time import localtime, mktime, strftime
__all__ = ["error","setfirstweekday","firstweekday","isleap",
"leapdays","weekday","monthrange","monthcalendar",
"prmonth","month","prcal","calendar","timegm",
"month_name", "month_abbr", "day_name", "day_abbr"]
# Exception raised for bad input (with string parameter for details)
error = ValueError
# Constants for months referenced later
January = 1
February = 2
# Number of days per month (except for February in leap years)
mdays = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
# This module used to have hard-coded lists of day and month names, as
# English strings. The classes following emulate a read-only version of
# that, but supply localized names. Note that the values are computed
# fresh on each call, in case the user changes locale between calls.
class _localized_month:
def __init__(self, format):
self.format = format
def __getitem__(self, i):
data = [strftime(self.format, (2001, j, 1, 12, 0, 0, 1, 1, 0))
for j in range(1, 13)]
data.insert(0, "")
return data[i]
def __len__(self):
return 13
class _localized_day:
def __init__(self, format):
self.format = format
def __getitem__(self, i):
# January 1, 2001, was a Monday.
data = [strftime(self.format, (2001, 1, j+1, 12, 0, 0, j, j+1, 0))
for j in range(7)]
return data[i]
def __len__(self_):
return 7
# Full and abbreviated names of weekdays
day_name = _localized_day('%A')
day_abbr = _localized_day('%a')
# Full and abbreviated names of months (1-based arrays!!!)
month_name = _localized_month('%B')
month_abbr = _localized_month('%b')
# Constants for weekdays
(MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY) = range(7)
_firstweekday = 0 # 0 = Monday, 6 = Sunday
def firstweekday():
return _firstweekday
def setfirstweekday(weekday):
"""Set weekday (Monday=0, Sunday=6) to start each week."""
global _firstweekday
if not MONDAY <= weekday <= SUNDAY:
raise ValueError, \
'bad weekday number; must be 0 (Monday) to 6 (Sunday)'
_firstweekday = weekday
def isleap(year):
"""Return 1 for leap years, 0 for non-leap years."""
return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)
def leapdays(y1, y2):
"""Return number of leap years in range [y1, y2).
Assume y1 <= y2."""
y1 -= 1
y2 -= 1
return (y2/4 - y1/4) - (y2/100 - y1/100) + (y2/400 - y1/400)
def weekday(year, month, day):
"""Return weekday (0-6 ~ Mon-Sun) for year (1970-...), month (1-12),
day (1-31)."""
secs = mktime((year, month, day, 0, 0, 0, 0, 0, 0))
tuple = localtime(secs)
return tuple[6]
def monthrange(year, month):
"""Return weekday (0-6 ~ Mon-Sun) and number of days (28-31) for
year, month."""
if not 1 <= month <= 12:
raise ValueError, 'bad month number'
day1 = weekday(year, month, 1)
ndays = mdays[month] + (month == February and isleap(year))
return day1, ndays
def monthcalendar(year, month):
"""Return a matrix representing a month's calendar.
Each row represents a week; days outside this month are zero."""
day1, ndays = monthrange(year, month)
rows = []
r7 = range(7)
day = (_firstweekday - day1 + 6) % 7 - 5 # for leading 0's in first week
while day <= ndays:
row = [0, 0, 0, 0, 0, 0, 0]
for i in r7:
if 1 <= day <= ndays: row[i] = day
day = day + 1
rows.append(row)
return rows
def prweek(theweek, width):
"""Print a single week (no newline)."""
print week(theweek, width),
def week(theweek, width):
"""Returns a single week in a string (no newline)."""
days = []
for day in theweek:
if day == 0:
s = ''
else:
s = '%2i' % day # right-align single-digit days
days.append(s.center(width))
return ' '.join(days)
def weekheader(width):
"""Return a header for a week."""
if width >= 9:
names = day_name
else:
names = day_abbr
days = []
for i in range(_firstweekday, _firstweekday + 7):
days.append(names[i%7][:width].center(width))
return ' '.join(days)
def prmonth(theyear, themonth, w=0, l=0):
"""Print a month's calendar."""
print month(theyear, themonth, w, l),
def month(theyear, themonth, w=0, l=0):
"""Return a month's calendar string (multi-line)."""
w = max(2, w)
l = max(1, l)
s = ((month_name[themonth] + ' ' + `theyear`).center(
7 * (w + 1) - 1).rstrip() +
'\n' * l + weekheader(w).rstrip() + '\n' * l)
for aweek in monthcalendar(theyear, themonth):
s = s + week(aweek, w).rstrip() + '\n' * l
return s[:-l] + '\n'
# Spacing of month columns for 3-column year calendar
_colwidth = 7*3 - 1 # Amount printed by prweek()
_spacing = 6 # Number of spaces between columns
def format3c(a, b, c, colwidth=_colwidth, spacing=_spacing):
"""Prints 3-column formatting for year calendars"""
print format3cstring(a, b, c, colwidth, spacing)
def format3cstring(a, b, c, colwidth=_colwidth, spacing=_spacing):
"""Returns a string formatted from 3 strings, centered within 3 columns."""
return (a.center(colwidth) + ' ' * spacing + b.center(colwidth) +
' ' * spacing + c.center(colwidth))
def prcal(year, w=0, l=0, c=_spacing):
"""Print a year's calendar."""
print calendar(year, w, l, c),
def calendar(year, w=0, l=0, c=_spacing):
"""Returns a year's calendar as a multi-line string."""
w = max(2, w)
l = max(1, l)
c = max(2, c)
colwidth = (w + 1) * 7 - 1
s = `year`.center(colwidth * 3 + c * 2).rstrip() + '\n' * l
header = weekheader(w)
header = format3cstring(header, header, header, colwidth, c).rstrip()
for q in range(January, January+12, 3):
s = (s + '\n' * l +
format3cstring(month_name[q], month_name[q+1], month_name[q+2],
colwidth, c).rstrip() +
'\n' * l + header + '\n' * l)
data = []
height = 0
for amonth in range(q, q + 3):
cal = monthcalendar(year, amonth)
if len(cal) > height:
height = len(cal)
data.append(cal)
for i in range(height):
weeks = []
for cal in data:
if i >= len(cal):
weeks.append('')
else:
weeks.append(week(cal[i], w))
s = s + format3cstring(weeks[0], weeks[1], weeks[2],
colwidth, c).rstrip() + '\n' * l
return s[:-l] + '\n'
EPOCH = 1970
def timegm(tuple):
"""Unrelated but handy function to calculate Unix timestamp from GMT."""
year, month, day, hour, minute, second = tuple[:6]
assert year >= EPOCH
assert 1 <= month <= 12
days = 365*(year-EPOCH) + leapdays(EPOCH, year)
for i in range(1, month):
days = days + mdays[i]
if month > 2 and isleap(year):
days = days + 1
days = days + day - 1
hours = days*24 + hour
minutes = hours*60 + minute
seconds = minutes*60 + second
return seconds