Is there a way to insure serial readline only reads when there is someething in the buffer?

[DR]

I am slowing working towards a live test of a sort of a driver to
deliver a packet to WeeWx.

Basically I have a Campbell Scientific datalogger gathering sensor
readings, and once every twenty seconds it writes a string to the serial
port.

My python 'driver' uses the serial readline to get the string, and it
does once things get going the first pass through.

I have the datalogger running all the time, and when I start my python
code the first pass is always reading a blank, so to speak, and all the
string conversions and such either return empty strings, or error out
with the attempt to float a value which isn't valid, yet.


I got around this for the time being by doing a len() on the readline
input string and only proceeding if the length is >1.


Then all seems to work since none of the splitting of the string into a
list and all has values rather than a blank to work with.

Somehow this seems inelegant and wonder if there is a better way to
approach this?  Despite Googling and reading about serial input methods
and pyserial and Geeks and RealPython I do not seem to find an answer.


Should I just put up with it seeming an odd way to do this and writing
an if...: at the beginning and let it go since it is just the first pass
of the python code reading the serial input buffer and works OK from
then on out?

Dale

[Vince Skahan]

If it works stably why worry it ? Basically sounds like a try/except block.