adding current date to a file name in a python script

[Fredrik Lundh]

markryde at gmail.com wrote:

> I am trying to add the current date to a file name in python script
> like thus:
>
> import os
> import sys
> import rpm
> import time
> import datetime
>
> today = datetime.date.today()
> print "The date is", today
> myFile = '/work/output1'
> myFile = myFile.join(today)
> myFile = myFile.join(".txt")
>
> print "myFile is",myFile
>
>
> running the scripts indeed prints the correct date ,
> but afterwards there is the following error:
>
> The date is 2006-01-29
> Traceback (most recent call last):
>   File "addDate.py", line 13, in ?
>     myFile = myFile.join(today)
> TypeError: sequence expected, datetime.date found
>
> How should I do this ?

datetime.date.today() returns a date object, not a string.

if the default string conversion is what you want, use str(today) to
convert to a string.

also note that "join" doesn't do what you think it does; "x.join(y)"
joins all members of the sequence y (which must all be strings) using
x as the separator.  this gives you a filename like

'.2/work/output10/work/output10/work/output16/work/output1-/work/output10/work/o
utput11/work/output1-/work/output12/work/output19t2/work/output10/work/output10/
work/output16/work/output1-/work/output10/work/output11/work/output1-/work/outpu
t12/work/output19x2/work/output10/work/output10/work/output16/work/output1-/work
/output10/work/output11/work/output1-/work/output12/work/output19t'

which is probably not what you want.

to fix this, you can use +=

    myFile = '/work/output1'
    myFile += str(today)
    myFile += ".txt"

or % formatting:

    myFile = '/work/output1%s.txt' % today

(here, "%s" does the str() call for you).

</F>