<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_uniform_time_weights(ds):
 """Append uniform time weights to a Dataset. All DataArrays with a time coordinate require a time weights coordinate. For Datasets read in without a time bounds coordinate or explicit time weights built in, aospy adds uniform time weights at each point in the time coordinate. Parameters ds : Dataset Input data Returns ------- Dataset """

    time = ds[TIME_STR]
    unit_interval = time.attrs['units'].split('since')[0].strip()
    time_weights = xr.ones_like(time)
    time_weights.attrs['units'] = unit_interval
    del time_weights.attrs['calendar']
    ds[TIME_WEIGHTS_STR] = time_weights
    return ds