Basic operations in Python datatable

datatable_basics.py

import numpy as np
import datatable as dt
from datatable import f, by, mean

# Reading a CSV
url = "https://raw.githubusercontent.com/mwaskom/seaborn-data/master/iris.csv"
tbl = dt.fread(url)

# Filtering rows
tbl = tbl[f.species != "setosa", :]

# Selecting columns
tbl = tbl[:, (f.species, f.sepal_length)]

# Adding a computed column (by reference)
tbl.cbind(tbl[:, {"sepal_length_sq" : np.square(f.sepal_length)}])

# Aggregating tables
agg_tbl = tbl[:, {"avg_sq_length" : mean(f.sepal_length_sq)}, by(f.species)]

# Outputting the result (and conversion to pandas)
agg_tbl.to_pandas()

As discussed here