Delete/Drop only the rows which has all values as NaN in pandas
The complete command is this:

df.dropna(axis = 0, how = 'all', inplace = True)


you must add inplace = True argument, if you want the dataframe to be actually updated. Alternatively, you would have to type:

df = df.dropna(axis = 0, how = 'all')


but that's less pythonic IMHO.