def iso_to_plotly_time_string(iso_string):
    """Remove timezone info and replace 'T' delimeter with ' ' (ws)."""
    if iso_string.split('-')[:3] == '00:00' or iso_string.split('+')[0
        ] == '00:00':
        raise Exception(
            """Plotly won't accept timestrings with timezone info.
All timestrings are assumed to be in UTC."""
            )
    iso_string = iso_string.replace('-00:00', '').replace('+00:00', '')
    if iso_string.endswith('T00:00:00'):
        return iso_string.replace('T00:00:00', '')
    else:
        return iso_string.replace('T', ' ')
