sscanf needed

[Uwe Mayer]

Hi,

I've got a ISO 8601 formatted date-time string which I need to read into a
datetime object.
Is there a shorter way than using regular expressions? Is there a sscanf
function as in C?

Thanks,
Uwe

[Fredrik Lundh]

Re: sscanf needed

Uwe Mayer wrote:
[color=blue]
> I've got a ISO 8601 formatted date-time string which I need to read into a
> datetime object.[/color]
[color=blue][color=green][color=darkred]
>>> import time
>>> help(time.strpt ime)[/color][/color][/color]
Help on built-in function strptime in module time:

strptime(...)
strptime(string , format) -> struct_time

Parse a string to a time tuple according to a format specification.
See the library reference manual for formatting codes (same as
strftime()).

</F>

[Leif B. Kristensen]

Re: sscanf needed

Uwe Mayer skrev:
[color=blue]
> Hi,
>
> I've got a ISO 8601 formatted date-time string which I need to read
> into a datetime object.[/color]

Look up time.strptime, it does exactly what you want.
--
Leif Biberg Kristensen

http://solumslekt.org/

[Kent Johnson]

Re: sscanf needed

Uwe Mayer wrote:[color=blue]
> Hi,
>
> I've got a ISO 8601 formatted date-time string which I need to read into a
> datetime object.[/color]

Something like this (adjust the format to suit):
import datetime, time
dt = datetime.dateti me(*time.strpti me(data, "%Y-%m-%d %H:%M:%S")[:6])

Kent

[Andrew E]

Re: sscanf needed

Uwe Mayer wrote:[color=blue]
> Hi,
>
> I've got a ISO 8601 formatted date-time string which I need to read into a
> datetime object.
> Is there a shorter way than using regular expressions? Is there a sscanf
> function as in C?[/color]

in addition to the other comments...

I like re, because it gives me the most control. See below.


import re
import datetime

class Converter:

def __init__( self ):
self.isoPattern = re.compile( "(\d\d\d\d)-(\d\d)-(\d\d)[tT
](\d\d):(\d\d):( \d\d)" )

def iso2date( self, isoDateString ):
match = self.isoPattern .match( isoDateString )
if not match: raise ValueError( "Not in ISO format: '%s'" %
isoDateString )

return datetime.dateti me(
int(match.group (1)),
int(match.group (2)),
int(match.group (3)),
int(match.group (4)),
int(match.group (5)),
int(match.group (6))
)

c = Converter()


def demo( iso ):
try:
date = c.iso2date( iso )
print "Input '%s' -> datetime: %s" % ( iso, date )
except ValueError, e:
print str(e)

demo( "2005-04-21T12:34:56" )
demo( "2005-04-21 12:34:57" )
demo( "2005-04-2 12:34:57" )

[Lee Harr]

Re: sscanf needed

On 2005-04-17, Andrew E <andrew@nospam. com> wrote:[color=blue]
> Uwe Mayer wrote:[color=green]
>> Hi,
>>
>> I've got a ISO 8601 formatted date-time string which I need to read into a
>> datetime object.
>> Is there a shorter way than using regular expressions? Is there a sscanf
>> function as in C?[/color]
>
> in addition to the other comments...
>
> I like re, because it gives me the most control. See below.
>
>
> import re
> import datetime
>
> class Converter:
>
> def __init__( self ):
> self.isoPattern = re.compile( "(\d\d\d\d)-(\d\d)-(\d\d)[tT
> ](\d\d):(\d\d):( \d\d)" )
>
> def iso2date( self, isoDateString ):
> match = self.isoPattern .match( isoDateString )
> if not match: raise ValueError( "Not in ISO format: '%s'" %
> isoDateString )
>
> return datetime.dateti me(
> int(match.group (1)),
> int(match.group (2)),
> int(match.group (3)),
> int(match.group (4)),
> int(match.group (5)),
> int(match.group (6))
> )
>
> c = Converter()
>
>
> def demo( iso ):
> try:
> date = c.iso2date( iso )
> print "Input '%s' -> datetime: %s" % ( iso, date )
> except ValueError, e:
> print str(e)
>
> demo( "2005-04-21T12:34:56" )
> demo( "2005-04-21 12:34:57" )
> demo( "2005-04-2 12:34:57" )
>
>[/color]


That's nice. We should get some code in to the module
so that it is simple to round-trip the default datetime
timestamps.