There are two quite different modes of operation with pywws. Traditionally :py:mod:`pywws.Hourly` would be run at regular intervals (usually an hour) from cron. This is suitable for fairly static websites, but more frequent updates can be useful for sites such as Weather Underground (http://www.wunderground.com/). The newer :py:mod:`pywws.LiveLog` program runs continuously and can upload data every 48 seconds.
Note that although this document (and the program name) refers to 'hourly' logging, you can run :py:mod:`pywws.Hourly` as often or as infrequently as you like, but don't try to run it more often than double your logging interval. For example, if your logging interval is 10 minutes, don't run :py:mod:`pywws.Hourly` more often than every 20 minutes.
First of all, you need to install pywws and make sure it can get data from your weather station. See :doc:`getstarted` for details.
Try running :py:mod:`pywws.Hourly` from the command line, with a high level of verbosity so you can see what's happening.
Use the pywws-hourly
command to run :py:mod:`pywws.Hourly`:
pywws-hourly -vvv ~/weather/data
Within five minutes (assuming you have set a 5 minute logging interval) you should see a 'live_data new ptr' message, followed by fetching any new data from the weather station and processing it.
.. versionchanged:: 14.04.dev1194 the ``pywws-hourly`` command replaced ``scripts/pywws-hourly.py``.
Open your weather.ini file with a text editor.
You should have a [paths]
section similar to the following (where xxx
is your user name):
[paths] work = /tmp/weather templates = /home/xxx/weather/templates/ graph_templates = /home/xxx/weather/graph_templates/ local_files = /home/xxx/weather/results/
Edit these to suit your installation and preferences.
work
is an existing temporary directory used to store intermediate files, templates
is the directory where you keep your text template files, graph_templates
is the directory where you keep your graph template files and local_files
is a directory where template output that is not uploaded to your web site is put.
Don't use the pywws example directories for your templates, as they will get over-written when you upgrade pywws.
Copy your text and graph templates to the appropriate directories.
You may find some of the examples provided with pywws useful to get started.
The pywws-version -v
command should show you where the examples are on your computer.
.. versionadded:: 14.04.dev1194 the ``pywws-version`` command.
In weather.ini you should have [logged]
, [hourly]
, [12 hourly]
and [daily]
sections similar to the following:
[logged] services = [] plot = [] text = [] [hourly] ...
These specify what :py:mod:`pywws.Hourly` should do when it is run.
Tasks in the [logged]
section are done every time there is new logged data, tasks in the [hourly]
section are done every hour, tasks in the [12 hourly]
section are done twice daily and tasks in the [daily]
section are done once per day.
The services
entry is a list of online weather services to upload data to.
The plot
and text
entries are lists of template files for plots and text files to be processed and, optionally, uploaded to your web site.
Add the names of your template files and weather services to the appropriate entries, for example:
[logged] services = ['underground', 'metoffice'] plot = [] text = [] [hourly] services = [] plot = ['7days.png.xml', '24hrs.png.xml', 'rose_24hrs.png.xml'] text = [('tweet.txt', 'T'), '24hrs.txt', '6hrs.txt', '7days.txt'] [12 hourly] services = [] plot = [] text = [] [daily] services = [] plot = ['28days.png.xml'] text = [('forecast.txt', 'T'), 'allmonths.txt']
Note the use of the 'T'
flag -- this tells pywws to send the template result to Twitter instead of uploading it to your ftp site.
You can test that all these are working by removing the [last update]
section from status.ini, then running :py:mod:`pywws.Hourly` again:
pywws-hourly -v ~/weather/data
.. versionadded:: 14.05.dev1211 ``[cron name]`` sections. If you need more flexibility in when tasks are done you can use ``[cron name]`` sections. See :doc:`weather_ini` for more detail.
.. versionchanged:: 13.06_r1015 added the ``'T'`` flag. Previously Twitter templates were listed separately in ``twitter`` entries in the ``[hourly]`` and other sections. The older syntax still works, but is deprecated.
.. versionchanged:: 13.05_r1009 the last update information was previously stored in weather.ini, with ``last update`` entries in several sections.
Most UNIX/Linux systems have a 'cron' daemon that can run programs at certain times, even if you are not logged in to the computer. You edit a 'crontab' file to specify what to run and when to run it. For example, to run :py:mod:`pywws.Hourly` every hour, at zero minutes past the hour:
0 * * * * pywws-hourly /home/xxx/weather/data
This might work, but if it didn't you probably won't get any error messages to tell you what went wrong. It's much better to run a script that runs :py:mod:`pywws.Hourly` and then emails you any output it produces. Here's the script I use:
#!/bin/sh # # weather station logger calling script export PATH=$PATH:/usr/local/bin if [ ! -d ~/weather/data/ ]; then exit fi log=/var/log/log-weather pywws-hourly -v ~/weather/data >$log 2>&1 # mail the log file /home/jim/scripts/email-log.sh $log "weather log"
You’ll need to edit this quite a lot to suit your file locations and so on, but it gives some idea of what to do.