error handling

[mcastorina]

a lot of arguments are passed directly to matplotlib which can cause errors

it would be nice to catch any errors and cleanly exit with a message

[mcastorina]

valid linestyles can be found with this code

from matplotlib import lines
lines.lineStyles.keys()

[mcastorina]

• Invalid CSV files
• Invalid line style
• Options not using the correct syntax (e.g. range uses : separator)