Converting a string to the most probable type

[Pierre Quentel]

Hi,

I would like to know if there is a module that converts a string to a
value of the "most probable type" ; for instance :
- if the string is "abcd" the value is the same string "abcd"
- string "123" : value = the integer 123
- string "-1.23" (or "-1,23" if the locale for decimals is ,) : value
= the float -1.23
- string "2008/03/06" (the format is also locale-dependant) : value =
datetime.date(2 008,03,06)

Like in spreadsheets, special prefixes could be used to force the
type : for instance '123 would be converted to the *string* "123"
instead of the *integer* 123

I could code it myself, but this wheel is probably already invented

Regards,
Pierre

[castironpi]

On Mar 8, 12:05*pm, Pierre Quentel <quentel.pie... @wanadoo.frwrot e:

>>def convert(x):

* * * * if '.' in x:
* * * * * * * * try: return float(x)
* * * * * * * * except ValueError: return x
* * * * else:
* * * * * * * * try: return int(x)
* * * * * * * * except: return x

>>convert('123' )

123

>>convert('123. 99')

123.98999999999 999

>>convert('hell o')

Hi,

That's fine for people who write floats with a "." ; but others learn
to enter them with ","

For the same float, the French write the literal 123.456.789,99 when
others write 123,456,789.99 ; for us, today is 8/3/2008 (or
08/03/2008) where for others it's 3/8/2008 or perhaps 2008/3/8

Popular spreadsheets know how to "guess" literals ; if the guess is
not correct users can usually specify the pattern to use. My question
was just to know if something similar had already been developed in
Python ; I understand that the answer is no

Thanks,
Pierre

In particular, you can retain access to the user/interface, and always
just query when probabilities aren't 100%. In general, retain access
to a higher power, such as offering a hook ( def butdonotguess( raw,
guesses ):). If you're making the decision, and a case-by-case is too
expensive, then you've made a policy, and someone gets shaft "'cause
policy". You can throw an exception that's guaranteed to be handled
or exits. '121212' isn't as bad as '121110'! If you want to find out
who and when writes dates like that, apply to PR. Obviously a person
knew at one point what the string was; how much is left?

P.S. def welltheydidthat thistime( raw, guesses ):.

[cokofreedom]

The trick in the case of when you do not want to guess, or the choices
grow too much, is to ask the user to tell you in what format they want
it and format according to their wishes.

Neatly avoids too much guessing and isn't much extra to add.

[John Machin]

On Mar 11, 3:19 am, cokofree...@gma il.com wrote:

The trick in the case of when you do not want to guess, or the choices
grow too much, is to ask the user to tell you in what format they want
it and format according to their wishes.

Neatly avoids too much guessing and isn't much extra to add.

The plot is about understanding input, not formatting output.

[Lie]

On Mar 11, 4:15*am, John Machin <sjmac...@lexic on.netwrote:

On Mar 11, 3:19 am, cokofree...@gma il.com wrote:

The trick in the case of when you do not want to guess, or the choices
grow too much, is to ask the user to tell you in what format they want
it and format according to their wishes.

Neatly avoids too much guessing and isn't much extra to add.

The plot is about understanding input, not formatting output.

And what he meant is simply to make an agreement with the user on how
he/she would format his/her input and to disallow input from formats
that haven't been agreed to avoid guessing. That is the cleanest and
most polite solution, although I'd suspect it would be considered less
user friendly by regular user although power user would be most happy
with that.