# (c) 2005 Clark C. Evans and contributors
# This module is part of the Python Paste Project and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
# Some of this code was funded by: http://prometheusresearch.com
"""
Date, Time, and Timespan Parsing Utilities
This module contains parsing support to create "human friendly"
``datetime`` object parsing. The explicit goal of these routines is
to provide a multi-format date/time support not unlike that found in
Microsoft Excel. In most approaches, the input is very "strict" to
prevent errors -- however, this approach is much more liberal since we
are assuming the user-interface is parroting back the normalized value
and thus the user has immediate feedback if the data is not typed in
correctly.
``parse_date`` and ``normalize_date``
These functions take a value like '9 jan 2007' and returns either an
``date`` object, or an ISO 8601 formatted date value such
as '2007-01-09'. There is an option to provide an Oracle database
style output as well, ``09 JAN 2007``, but this is not the default.
This module always treats '/' delimiters as using US date order
(since the author's clients are US based), hence '1/9/2007' is
January 9th. Since this module treats the '-' as following
European order this supports both modes of data-entry; together
with immediate parroting back the result to the screen, the author
has found this approach to work well in pratice.
``parse_time`` and ``normalize_time``
These functions take a value like '1 pm' and returns either an
``time`` object, or an ISO 8601 formatted 24h clock time
such as '13:00'. There is an option to provide for US style time
values, '1:00 PM', however this is not the default.
``parse_datetime`` and ``normalize_datetime``
These functions take a value like '9 jan 2007 at 1 pm' and returns
either an ``datetime`` object, or an ISO 8601 formatted
return (without the T) such as '2007-01-09 13:00'. There is an
option to provide for Oracle / US style, '09 JAN 2007 @ 1:00 PM',
however this is not the default.
``parse_delta`` and ``normalize_delta``
These functions take a value like '1h 15m' and returns either an
``timedelta`` object, or an 2-decimal fixed-point
numerical value in hours, such as '1.25'. The rationale is to
support meeting or time-billing lengths, not to be an accurate
representation in mili-seconds. As such not all valid
``timedelta`` values will have a normalized representation.
"""
from datetime import timedelta, time, date
from time import localtime
__all__ = ['parse_timedelta', 'normalize_timedelta',
'parse_time', 'normalize_time',
'parse_date', 'normalize_date']
def _number(val):
try:
return int(val)
except:
return None
#
# timedelta
#
def parse_timedelta(val):
"""
returns a ``timedelta`` object, or None
"""
if not val:
return None
val = val.lower()
if "." in val:
val = float(val)
return timedelta(hours=int(val), minutes=60*(val % 1.0))
fHour = ("h" in val or ":" in val)
fMin = ("m" in val or ":" in val)
for noise in "minu:teshour()":
val = val.replace(noise, ' ')
val = val.strip()
val = val.split()
hr = 0.0
mi = 0
val.reverse()
if fHour:
hr = int(val.pop())
if fMin:
mi = int(val.pop())
if len(val) > 0 and not hr:
hr = int(val.pop())
return timedelta(hours=hr, minutes=mi)
def normalize_timedelta(val):
"""
produces a normalized string value of the timedelta
This module returns a normalized time span value consisting of the
number of hours in fractional form. For example '1h 15min' is
formatted as 01.25.
"""
if type(val) == str:
val = parse_timedelta(val)
if not val:
return ''
hr = val.seconds/3600
mn = (val.seconds % 3600)/60
return "%d.%02d" % (hr, mn * 100/60)
#
# time
#
def parse_time(val):
if not val:
return None
hr = mi = 0
val = val.lower()
amflag = (-1 != val.find('a')) # set if AM is found
pmflag = (-1 != val.find('p')) # set if PM is found
for noise in ":amp.":
val = val.replace(noise, ' ')
val = val.split()
if len(val) > 1:
hr = int(val[0])
mi = int(val[1])
else:
val = val[0]
if len(val) < 1:
pass
elif 'now' == val:
tm = localtime()
hr = tm[3]
mi = tm[4]
elif 'noon' == val:
hr = 12
elif len(val) < 3:
hr = int(val)
if not amflag and not pmflag and hr < 7:
hr += 12
elif len(val) < 5:
hr = int(val[:-2])
mi = int(val[-2:])
else:
hr = int(val[:1])
if amflag and hr >= 12:
hr = hr - 12
if pmflag and hr < 12:
hr = hr + 12
return time(hr, mi)
def normalize_time(value, ampm):
if not value:
return ''
if type(value) == str:
value = parse_time(value)
if not ampm:
return "%02d:%02d" % (value.hour, value.minute)
hr = value.hour
am = "AM"
if hr < 1 or hr > 23:
hr = 12
elif hr >= 12:
am = "PM"
if hr > 12:
hr = hr - 12
return "%02d:%02d %s" % (hr, value.minute, am)
#
# Date Processing
#
_one_day = timedelta(days=1)
_str2num = {'jan':1, 'feb':2, 'mar':3, 'apr':4, 'may':5, 'jun':6,
'jul':7, 'aug':8, 'sep':9, 'oct':10, 'nov':11, 'dec':12 }
def _month(val):
for (key, mon) in _str2num.items():
if key in val:
return mon
raise TypeError("unknown month '%s'" % val)
_days_in_month = {1: 31, 2: 28, 3: 31, 4: 30, 5: 31, 6: 30,
7: 31, 8: 31, 9: 30, 10: 31, 11: 30, 12: 31,
}
_num2str = {1: 'Jan', 2: 'Feb', 3: 'Mar', 4: 'Apr', 5: 'May', 6: 'Jun',
7: 'Jul', 8: 'Aug', 9: 'Sep', 10: 'Oct', 11: 'Nov', 12: 'Dec',
}
_wkdy = ("mon", "tue", "wed", "thu", "fri", "sat", "sun")
def parse_date(val):
if not(val):
return None
val = val.lower()
now = None
# optimized check for YYYY-MM-DD
strict = val.split("-")
if len(strict) == 3:
(y, m, d) = strict
if "+" in d:
d = d.split("+")[0]
if " " in d:
d = d.split(" ")[0]
try:
now = date(int(y), int(m), int(d))
val = "xxx" + val[10:]
except ValueError:
pass
# allow for 'now', 'mon', 'tue', etc.
if not now:
chk = val[:3]
if chk in ('now','tod'):
now = date.today()
elif chk in _wkdy:
now = date.today()
idx = list(_wkdy).index(chk) + 1
while now.isoweekday() != idx:
now += _one_day
# allow dates to be modified via + or - /w number of days, so
# that now+3 is three days from now
if now:
tail = val[3:].strip()
tail = tail.replace("+"," +").replace("-"," -")
for item in tail.split():
try:
days = int(item)
except ValueError:
pass
else:
now += timedelta(days=days)
return now
# ok, standard parsing
yr = mo = dy = None
for noise in ('/', '-', ',', '*'):
val = val.replace(noise, ' ')
for noise in _wkdy:
val = val.replace(noise, ' ')
out = []
last = False
ldig = False
for ch in val:
if ch.isdigit():
if last and not ldig:
out.append(' ')
last = ldig = True
else:
if ldig:
out.append(' ')
ldig = False
last = True
out.append(ch)
val = "".join(out).split()
if 3 == len(val):
a = _number(val[0])
b = _number(val[1])
c = _number(val[2])
if len(val[0]) == 4:
yr = a
if b: # 1999 6 23
mo = b
dy = c
else: # 1999 Jun 23
mo = _month(val[1])
dy = c
elif a is not None and a > 0:
yr = c
if len(val[2]) < 4:
raise TypeError("four digit year required")
if b: # 6 23 1999
dy = b
mo = a
else: # 23 Jun 1999
dy = a
mo = _month(val[1])
else: # Jun 23, 2000
dy = b
yr = c
if len(val[2]) < 4:
raise TypeError("four digit year required")
mo = _month(val[0])
elif 2 == len(val):
a = _number(val[0])
b = _number(val[1])
if a is not None and a > 999:
yr = a
dy = 1
if b is not None and b > 0: # 1999 6
mo = b
else: # 1999 Jun
mo = _month(val[1])
elif a is not None and a > 0:
if b is not None and b > 999: # 6 1999
mo = a
yr = b
dy = 1
elif b is not None and b > 0: # 6 23
mo = a
dy = b
else: # 23 Jun
dy = a
mo = _month(val[1])
else:
if b > 999: # Jun 2001
yr = b
dy = 1
else: # Jun 23
dy = b
mo = _month(val[0])
elif 1 == len(val):
val = val[0]
if not val.isdigit():
mo = _month(val)
if mo is not None:
dy = 1
else:
v = _number(val)
val = str(v)
if 8 == len(val): # 20010623
yr = _number(val[:4])
mo = _number(val[4:6])
dy = _number(val[6:])
elif len(val) in (3,4):
if v is not None and v > 1300: # 2004
yr = v
mo = 1
dy = 1
else: # 1202
mo = _number(val[:-2])
dy = _number(val[-2:])
elif v < 32:
dy = v
else:
raise TypeError("four digit year required")
tm = localtime()
if mo is None:
mo = tm[1]
if dy is None:
dy = tm[2]
if yr is None:
yr = tm[0]
return date(yr, mo, dy)
def normalize_date(val, iso8601=True):
if not val:
return ''
if type(val) == str:
val = parse_date(val)
if iso8601:
return "%4d-%02d-%02d" % (val.year, val.month, val.day)
return "%02d %s %4d" % (val.day, _num2str[val.month], val.year)