Change fields datatypes

[daviddavo]

Now, the data is saved in DataFrames with the default datatype. The objective is to use a suitable type for each field (for example, changing unix epochs to datetime, the network from string to categorical, etc.).

This would save a lot of space both in RAM and disk space.

Further reading

• https://pandas.pydata.org/pandas-docs/stable/user_guide/scale.html