get the terminal's size

[Peter Otten]

Grant Edwards wrote:

os.environ["COLUMNS"]

> [...] will tell you the terminal size at the time Python was started.

I admit that none of my scripts is ambitious enough to try and track changes 
in terminal size. 

But still, Grant's post prompted me to reread the doc and source of 
shutil.get_terminal_size(), and I think I should warn you that the 
environment variables take precedence over ioctl()-based detection in 
os.get_terminal_size().

I'll keep the exports for now because even for a pipe

$ python3 -c 'import shutil; print(shutil.get_terminal_size())' | cat
os.terminal_size(columns=80, lines=24)
$ export LINES COLUMNS
$ python3 -c 'import shutil; print(shutil.get_terminal_size())' | cat
os.terminal_size(columns=137, lines=42)

the current terminal is usually my final target.