파이썬 - Pandas 실습 -2

winemag-data.csv 파일을 reviews 로 읽는다.

import pandas as pd

reviews = pd.read_csv("winemag-data.csv",index_col = 0)

인덱스를 title 컬럼으로 셋팅한다.

# reviews.set_index('title', inplace=True)
reviews = reviews.set_index('title')

먼저 데이터가 비어있느것이 있는지 확인한다.

reviews.isna().sum()

country                     63
description                  0
designation              37465
points                       0
price                     8996
province                    63
region_1                 21247
region_2                 79460
taster_name              26244
taster_twitter_handle    31213
variety                      1
winery                       0
dtype: int64

그리고나서, 가격이 없는 데이터는 빼고, 데이터셋을 가져온다.

data_set = reviews.dropna(subset=['price'])
data_set.head()

	country	description	designation	points	price	province	region_1	region_2	taster_name	taster_twitter_handle	variety	winery
title
Quinta dos Avidagos 2011 Avidagos Red (Douro)	Portugal	This is ripe and fruity, a wine that is smooth...	Avidagos	87	15.0	Douro	NaN	NaN	Roger Voss	@vossroger	Portuguese Red	Quinta dos Avidagos
Rainstorm 2013 Pinot Gris (Willamette Valley)	US	Tart and snappy, the flavors of lime flesh and...	NaN	87	14.0	Oregon	Willamette Valley	Willamette Valley	Paul Gregutt	@paulgwine	Pinot Gris	Rainstorm
St. Julian 2013 Reserve Late Harvest Riesling (Lake Michigan Shore)	US	Pineapple rind, lemon pith and orange blossom ...	Reserve Late Harvest	87	13.0	Michigan	Lake Michigan Shore	NaN	Alexander Peartree	NaN	Riesling	St. Julian
Sweet Cheeks 2012 Vintner's Reserve Wild Child Block Pinot Noir (Willamette Valley)	US	Much like the regular bottling from 2012, this...	Vintner's Reserve Wild Child Block	87	65.0	Oregon	Willamette Valley	Willamette Valley	Paul Gregutt	@paulgwine	Pinot Noir	Sweet Cheeks
Tandem 2011 Ars In Vitro Tempranillo-Merlot (Navarra)	Spain	Blackberry and raspberry aromas show a typical...	Ars In Vitro	87	15.0	Northern Spain	Navarra	NaN	Michael Schachner	@wineschach	Tempranillo-Merlot	Tandem

reviews.shape

(129971, 12)

리뷰에 새로운 컬럼 critic 만들고, everyone 이라고 값 넣는다.

reviews['critic'] = 'everyone'

reviews.head(2)

	country	description	designation	points	price	province	region_1	region_2	taster_name	taster_twitter_handle	variety	winery	critic
title
Nicosia 2013 Vulkà Bianco (Etna)	Italy	Aromas include tropical fruit, broom, brimston...	Vulkà Bianco	87	NaN	Sicily & Sardinia	Etna	NaN	Kerin O’Keefe	@kerinokeefe	White Blend	Nicosia	everyone
Quinta dos Avidagos 2011 Avidagos Red (Douro)	Portugal	This is ripe and fruity, a wine that is smooth...	Avidagos	87	15.0	Douro	NaN	NaN	Roger Voss	@vossroger	Portuguese Red	Quinta dos Avidagos	everyone

리뷰의 포인트 컬럼은 수치로 되어있다. 이 컬럼의 기초통계데이터를 확인하시오. (평균, 최대 최소 등)

reviews["points"].describe()

count    129971.000000
mean         88.447138
std           3.039730
min          80.000000
25%          86.000000
50%          88.000000
75%          91.000000
max         100.000000
Name: points, dtype: float64

점수를 100점 맞은 와인의 데이터를 가져오시오.

wine_data = reviews.loc[reviews['points'] == 100,]

wine_data.head()

	country	description	designation	points	price	province	region_1	region_2	taster_name	taster_twitter_handle	variety	winery	critic
title
Chambers Rosewood Vineyards NV Rare Muscat (Rutherglen)	Australia	This wine contains some material over 100 year...	Rare	100	350.0	Victoria	Rutherglen	NaN	Joe Czerwinski	@JoeCz	Muscat	Chambers Rosewood Vineyards	everyone
Avignonesi 1995 Occhio di Pernice (Vin Santo di Montepulciano)	Italy	Thick as molasses and dark as caramelized brow...	Occhio di Pernice	100	210.0	Tuscany	Vin Santo di Montepulciano	NaN	NaN	NaN	Prugnolo Gentile	Avignonesi	everyone
Krug 2002 Brut (Champagne)	France	This is a fabulous wine from the greatest Cham...	Brut	100	259.0	Champagne	Champagne	NaN	Roger Voss	@vossroger	Champagne Blend	Krug	everyone
Tenuta dell'Ornellaia 2007 Masseto Merlot (Toscana)	Italy	A perfect wine from a classic vintage, the 200...	Masseto	100	460.0	Tuscany	Toscana	NaN	NaN	NaN	Merlot	Tenuta dell'Ornellaia	everyone
Casa Ferreirinha 2008 Barca-Velha Red (Douro)	Portugal	This is the latest release of what has long be...	Barca-Velha	100	450.0	Douro	NaN	NaN	Roger Voss	@vossroger	Portuguese Red	Casa Ferreirinha	everyone

taster_name 컬럼은 사람 이름으로 되어있다. 몇명의 사람들이 평가를 한것인까?

# unique의 수.
reviews['taster_name'].describe()

count         103727
unique            19
top       Roger Voss
freq           25514
Name: taster_name, dtype: object

리뷰 포인트의 평균을 구하시오

reviews["points"].mean()

88.44713820775404

테스터들의 이름을 전부 확인하시오

reviews["taster_name"].unique()

array(['Kerin O’Keefe', 'Roger Voss', 'Paul Gregutt',
       'Alexander Peartree', 'Michael Schachner', 'Anna Lee C. Iijima',
       'Virginie Boone', 'Matt Kettmann', nan, 'Sean P. Sullivan',
       'Jim Gordon', 'Joe Czerwinski', 'Anne Krebiehl\xa0MW',
       'Lauren Buzzeo', 'Mike DeSimone', 'Jeff Jenssen',
       'Susan Kostrzewa', 'Carrie Dykes', 'Fiona Adams',
       'Christina Pickard'], dtype=object)

각 테스터들은, 각각 몇개의 와인을 테스트 했는지 확인하시오. ( 테스터 이름, 갯수 )

reviews['taster_name'].value_counts()

Roger Voss            25514
Michael Schachner     15134
Kerin O’Keefe         10776
Virginie Boone         9537
Paul Gregutt           9532
Matt Kettmann          6332
Joe Czerwinski         5147
Sean P. Sullivan       4966
Anna Lee C. Iijima     4415
Jim Gordon             4177
Anne Krebiehl MW       3685
Lauren Buzzeo          1835
Susan Kostrzewa        1085
Mike DeSimone           514
Jeff Jenssen            491
Alexander Peartree      415
Carrie Dykes            139
Fiona Adams              27
Christina Pickard         6
Name: taster_name, dtype: int64

리뷰의 포인트의 평균을 구하고, 리뷰의 포인트값이, 평균보다 큰 데이터 (즉, 평가가 좋은 와인) 만 가져오시오.

good_wine = reviews['points']> reviews['points'].mean()

reviews.loc[good_wine, ].head()

	country	description	designation	points	price	province	region_1	region_2	taster_name	taster_twitter_handle	variety	winery	critic
title
Dopff & Irion 2004 Schoenenbourg Grand Cru Vendanges Tardives Riesling (Alsace)	France	Medium-gold in color. Complex and inviting nos...	Schoenenbourg Grand Cru Vendanges Tardives	92	80.0	Alsace	Alsace	NaN	NaN	NaN	Riesling	Dopff & Irion	everyone
Ceretto 2003 Bricco Rocche Prapó (Barolo)	Italy	Slightly backward, particularly given the vint...	Bricco Rocche Prapó	92	70.0	Piedmont	Barolo	NaN	NaN	NaN	Nebbiolo	Ceretto	everyone
Matrix 2007 Stuhlmuller Vineyard Chardonnay (Alexander Valley)	US	The vineyard is one of the better Chardonnay s...	Stuhlmuller Vineyard	92	36.0	California	Alexander Valley	Sonoma	NaN	NaN	Chardonnay	Matrix	everyone
Mauritson 2007 Rockpile Cemetary Vineyard Zinfandel (Rockpile)	US	Defines Rockpile Zinfandel in intensity of fru...	Rockpile Cemetary Vineyard	92	39.0	California	Rockpile	Sonoma	NaN	NaN	Zinfandel	Mauritson	everyone
Henry's Drive Vignerons 2006 Parson's Flat Shiraz-Cabernet Sauvignon (Padthaway)	Australia	The blend is roughly two-thirds Shiraz and one...	Parson's Flat	92	40.0	South Australia	Padthaway	NaN	Joe Czerwinski	@JoeCz	Shiraz-Cabernet Sauvignon	Henry's Drive Vignerons	everyone