Tabelle pivot
Manipolazione dei dati con pandas
Maggie Matsui
Senior Content Developer at DataCamp
Raggruppa in tabella pivot
dogs.groupby("color")["weight_kg"].mean()
color
Black 26
Brown 24
Gray 17
Tan 2
White 74
Name: weight_kg, dtype: int64
dogs.pivot_table(values="weight_kg",
index="color")
weight_kg
color
Black 26.5
Brown 24.0
Gray 17.0
Tan 2.0
White 74.0
Statistiche diverse
dogs.pivot_table(values="weight_kg", index="color", aggfunc="median")
weight_kg
color
Black 26.5
Brown 24.0
Gray 17.0
Tan 2.0
White 74.0
Statistiche multiple
dogs.pivot_table(values="weight_kg", index="color", aggfunc=["mean", "median"])
mean median
weight_kg weight_kg
color
Black 26.5 26.5
Brown 24.0 24.0
Gray 17.0 17.0
Tan 2.0 2.0
White 74.0 74.0
Punta su due variabili
dogs.groupby(["color", "breed"])["weight_kg"].mean()
dogs.pivot_table(values="weight_kg", index="color", columns="breed")
breed Chihuahua Chow Chow Labrador Poodle Schnauzer St. Bernard
color
Black NaN NaN 29.0 24.0 NaN NaN
Brown NaN 24.0 24.0 NaN NaN NaN
Gray NaN NaN NaN NaN 17.0 NaN
Tan 2.0 NaN NaN NaN NaN NaN
White NaN NaN NaN NaN NaN 74.0
Come inserire i valori mancanti nelle tabelle pivot
dogs.pivot_table(values="weight_kg", index="color", columns="breed", fill_value=0)
breed Chihuahua Chow Chow Labrador Poodle Schnauzer St. Bernard
color
Black 0 0 29 24 0 0
Brown 0 24 24 0 0 0
Gray 0 0 0 0 17 0
Tan 2 0 0 0 0 0
White 0 0 0 0 0 74
Riepilogo con tabelle pivot
dogs.pivot_table(values="weight_kg", index="color", columns="breed",
fill_value=0, margins=True)
breed Chihuahua Chow Chow Labrador Poodle Schnauzer St. Bernard All
color
Black 0 0 29 24 0 0 26.500000
Brown 0 24 24 0 0 0 24.000000
Gray 0 0 0 0 17 0 17.000000
Tan 2 0 0 0 0 0 2.000000
White 0 0 0 0 0 74 74.000000
All 2 24 26 24 17 74 27.714286
Passiamo alla pratica!
Manipolazione dei dati con pandas
