Make function for handling time or reuse an existing one

[kratman]

The following code was added in #4073:

            elif term.endswith("s"):
                end_time_s = term.split("s")[0]
                termination_dict["time"] = (float(end_time_s), "s")
            elif term.endswith("min"):
                end_time_s = term.split("min")[0]
                termination_dict["time"] = (float(end_time_s) * 60, "s")
            elif term.endswith("h"):
                end_time_s = term.split("h")[0]
                termination_dict["time"] = (float(end_time_s) * 3600, "s")

This should probably be converted to a function. For example, if a space is required in the string then:

elif temer.split(" ")[1] in ["h", "min", "s"]:
    end_time = term.split(" ")[0]
    unit = term.split(" ")[1]
    termination_dict["time"] = convert_time_to_seconds(end_time, unit)

[kratman]

Note: Part of this ticket is finding out if there are other instances where this change can be made. So whoever takes this up, please search for other time conversions

[valentinsulzer]

There is a _convert_time_to_seconds function https://github.com/pybamm-team/PyBaMM/blob/develop/pybamm/experiment/step/base_step.py#L344

[agriyakhetarpal]

From #4073 (comment) I think you'll need to comment here, @mleot, so that GitHub can add your name to the list of potential assignees

[mleot]

Got it, commenting here.