Re: [Matplotlib-users] dates for x-axis

[Benjamin R. <ben...@ou...>]

On Thu, Apr 19, 2012 at 1:21 PM, Goyo <goy...@gm...> wrote:

> El día 19 de abril de 2012 05:31, questions anon
> <que...@gm...> escribió:
> > Thank you, I was able to get it to work but only if I imported datetime
> > within the loop, otherwise I ended up with the
> > AttributeError: type object 'datetime.datetime' has no attribute
> 'datetime'
> > and if I added 'import datetime' at the top of my script it had an error
> > where I loop through combining each month
> > "    stop_month = datetime(2011, 03, 01)
> > TypeError: 'module' object is not callable"
>
> If you can write a standalone, minimal executable script which
> reproduces the problem I'll take a look. Send it as an attachement and
> add sample data files if necessary.
>
> Goyo
>
>
The issue is that there is a slight mixup in namespaces.  There is a module
called datetime, and that module contains a class object called datetime.
So, if your imports at the top are "import datetime", then all your
module-related stuff need to be prepended with "datetime.". But, if your
imports at the top are "from datetime import datetime", then you can use
the object freely, but you can't use anything else from the module unless
you also import it.

Here is the tricky part.  In your code, you did the following:

from datetime import datetime

If you then did:

import datetime

depending on the order the two were, one would overwrite the other.  You
can only have one thing called "datetime".  Personally, I would do one of
two things:

import datetime as dt

and use "dt.datetime()" to create datetime objects as well as call
functions like "dt.strftime()". Or, do

from datetime import datetime, date, timedelta, strftime

and get replace calls like "datetime.datetime()" and "datetime.strftime()"
with just "datetime()" and "strftime()".

I hope that clears things up.  Namespaces are a honking good idea, but
having objects be the same exact name as a module gets confusing very
easily.

Cheers!
Ben Root