import pandas as pd
import numpy as np

swim = pd.read_csv("http://www.mosaic-web.org/go/datasets/swim100m.csv")

swim.head()

swim.columns

swim.describe()

swim.shape

swim.year.mean()

swim["year"].min()

np.min(swim["year"])

np.min(swim.year)

year.min()

swim.groupby('sex')['year'].mean()

swim.year.sqrt()

swim.year.apply(func=np.sqrt).head() # There are 62 cases in total

np.sqrt(swim.year).head() # Again, there are 62 cases in total

swim['minutes'] = swim.time/60. # or swim['time']/60.

swim.insert(1, 'mins', swim.time/60.)

swim['time'] = swim.time/60.

swim.head()