gt.load.seaglider_show_variables doesn't work from command line

[callumrollo]

gt.load.seaglider_show_variables uses pandas dataframe .style to make a pretty return. This will not work if run from plain python/command line application

To Reproduce

1. Start a Python session from the command line and load glidertools import glidertools as gt
2. Get some Seaglider .nc files and point at them filenames = 'data_marina/p*.nc'
3. gt.load.seaglider_show_variables(filenames)
4. Get the return:
   <pandas.io.formats.style.Styler at 0x7fe6bbf98af0>

Expected behavior
Print out a pretty table with all the variables in those .nc files

Cause

The styling commands at lines 53-59 of gt.load.seaglider:

    vars = (
        vars.sort_values(["dims", "name"])
        .reset_index(drop=True)
        .loc[:, ["dims", "name", "units", "comment"]]
        .set_index("name")
        .style
    )

System

• Linux Ubuntu 20.04
• Python from terminal session

Proposed fix

• Detect if user is running jupyter-like environment. If not, simply print the table, don't style it.

Credit to Marina Azaneu at UEA for discovering this.