[Tutor] Variable and a raw string

[David L Neil]

On 21/01/20 8:50 AM, Alessandro Caudilho wrote:
> Hello all
> 
> my code below:
> 
> ============================
> from datetime import datetime
> 
> state = 'colorado/us'
> 
> with open('/home/user/' + state + '.txt', 'a') as f:
>      time = datetime.today().strftime('%Y-%m-%d %H:%M:%S')
>      f.write(time)
>      f.close()
> ============================
> 
> And I get FileNotFoundError: [Errno 2] No such file or directory: "/home/user/colorado/us'.txt"


Did you re-type the code or did you copy-paste it from the editor into 
this email msg???
(the mixture of quotation-marks/double-quotes and 
apostrophe/single-quote in the err.msg, indicates that the above code is 
NOT the original)

1 if the code is being run (by "user") from his/her home-directory (ie 
/home/user) then all that may be omitted from the open()

2 if your intent is to separate each US State into its own directory, 
then would "...US/Colorado..." make for a better stepwise-refinement?

3 otherwise if the "us" part is merely a label, perhaps to distinguish 
from some "colorado" in another country, then please see previous responses.

4 Please review open-append in 
https://docs.python.org/3/library/functions.html?highlight=open#open 
(see also "absolute" and "relative", per (1) above). What happens if one 
opens a file in a directory which does not (yet) exist? How does this 
differ from attempting to open a file which does not exist (read) or 
does not yet exist (append)? (experiment in the Python REPL)

5 given that the file is being processed in-context (with), the close() 
is unnecessary, because it is provided auto-magically as part of the 
context-manager 
(https://docs.python.org/3/reference/compound_stmts.html#the-with-statement)

-- 
Regards =dn