UCL葡萄酒（red white wine quality）数据集字段解释、数据导入实战

#数据字段说明

#导入数据

#数据字段说明

葡萄酒分为白葡萄酒和红葡萄酒两类。

此处为白葡萄酒：增加一个类型字段则为包含白葡萄和红葡萄的葡萄酒数据集

两个数据集在单独拆分的时候quality的类别可能有轻微差异。

固定酸度:大多数与葡萄酒有关的酸或固定的或不挥发的(不易蒸发)
挥发性酸味:葡萄酒中醋酸的含量过高，会产生令人不快的醋味
柠檬酸:少量的柠檬酸可以增加葡萄酒的新鲜度和风味
残糖:发酵结束后的残糖量，每升1克以下的酒很少，45克以上的酒被认为是甜的
氯化物:酒中盐的含量
游离二氧化硫:SO2以游离形式存在于SO2分子(作为溶解气体)与亚硫酸氢盐离子之间的平衡状态;它可以防止葡萄酒中的微生物生长和氧化
总二氧化硫:SO2游离态和结合态的量;在低浓度的情况下，SO2在葡萄酒中几乎检测不到，但当游离SO2浓度超过50ppm时，SO2在葡萄酒的嗅觉和味觉中就会变得明显
密度:根据酒精和糖含量的百分比，水的密度接近于水的密度
pH值:描述葡萄酒的酸性或碱性程度，从0(非常酸)到14(非常碱性);大多数葡萄酒的pH值在3-4之间
硫酸盐:一种葡萄酒添加剂，可以提高二氧化硫气体(SO2)水平，起到抗菌和抗氧化剂的作用
酒精:葡萄酒中酒精含量的百分比
质量:输出变量(根据感官数据，评分0 - 10),有专门的评酒师和调酒师的职业

White Wine Quality dataset which is a tidy data set. This data set contains 4,898 white wines with 11 variables on quantifying the chemical properties of each wine. At least 3 wine experts rated the quality of each wine, providing a rating between 0 (very bad) and 10 (very excellent).

**fixed acidity** : most acids involved with wine or fixed or nonvolatile (do not evaporate readily)

**volatile acidity_** : the amount of acetic acid in wine, which at too high of levels can lead to an unpleasant, vinegar taste

**citric acid** : found in small quantities, citric acid can add ‘freshness’ and flavor to wines

**residual sugar** : the amount of sugar remaining after fermentation stops, it’s rare to find wines with less than 1 gram/liter and wines with greater than 45 grams/liter are considered sweet

**chlorides** : the amount of salt in the wine

**free sulfur dioxide** : the free form of SO2 exists in equilibrium between molecular SO2 (as a dissolved gas) and bisul-fite ion; it prevents microbial growth and the oxidation of wine

**total sulfur dioxide**: amount of free and bound forms of S02; in low concentrations, SO2 is mostly undetectable in wine, but at free SO2 concentrations over 50 ppm, SO2 becomes evident in the nose and taste of wine

**density** : the density of water is close to that of water depending on the percent alcohol and sugar con-tent

**pH** : describes how acidic or basic a wine is on a scale from 0 (very acidic) to 14 (very basic); most wines are between 3–4 on the pH scale

**sulphates** : a wine additive which can contribute to sulfur dioxide gas (S02) levels, which acts as an antimicrobial and antioxidant

**alcohol** : the percent alcohol content of the wine

**quality** : output variable (based on sensory data, score between 0 and 10)

葡萄酒认证包括物理化学测试，例如密度，pH，酒精含量，固定和挥发性酸度的测定等。

可以在UCI机器学习存储库中找到该数据集。葡萄酒分为白葡萄酒和红葡萄酒两类。
该分析涉及白葡萄酒，并基于数据集中显示的13个变量/特征：
固定酸度
挥发性酸度
柠檬酸
残留糖
氯化物
游离二氧化硫
总二氧化硫
密度
pH值
硫酸盐
酒精
质量

#导入数据

df = pd.read_csv('winequality-white.csv', sep=';')
df.head()
df.tail()
# df.sample(5)

UCL白葡萄酒和红葡萄酒合起来的数据集，增加一个类型字段指示是白葡萄酒还是红葡萄酒

## 'data.frame':    3000 obs. of  15 variables:
##  $ X                   : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ fixed.acidity       : num  7.4 7.8 7.8 11.2 7.4 7.4 7.9 7.3 7.8 7.5 ...
##  $ volatile.acidity    : num  0.7 0.88 0.76 0.28 0.7 0.66 0.6 0.65 0.58 0.5 ...
##  $ citric.acid         : num  0 0 0.04 0.56 0 0 0.06 0 0.02 0.36 ...
##  $ residual.sugar      : num  1.9 2.6 2.3 1.9 1.9 1.8 1.6 1.2 2 6.1 ...
##  $ chlorides           : num  0.076 0.098 0.092 0.075 0.076 0.075 0.069 0.065 0.073 0.071 ...
##  $ free.sulfur.dioxide : num  11 25 15 17 11 13 15 15 9 17 ...
##  $ total.sulfur.dioxide: num  34 67 54 60 34 40 59 21 18 102 ...
##  $ density             : num  0.998 0.997 0.997 0.998 0.998 ...
##  $ pH                  : num  3.51 3.2 3.26 3.16 3.51 3.51 3.3 3.39 3.36 3.35 ...
##  $ sulphates           : num  0.56 0.68 0.65 0.58 0.56 0.56 0.46 0.47 0.57 0.8 ...
##  $ alcohol             : num  9.4 9.8 9.8 9.8 9.4 9.4 9.4 10 9.5 10.5 ...
##  $ quality             : int  5 5 5 6 5 5 5 7 7 5 ...
##  $ type                : Factor w/ 2 levels "Red","White": 1 1 1 1 1 1 1 1 1 1 ...
##  $ quality.bucket      : Factor w/ 3 levels "Low","Medium",..: 2 2 2 2 2 2 2 3 3 2 ...

参考：kaggle+Predicting White Wine Quality

参考：UCL

参考：泰坦尼克号数据集_Kaggle | 泰坦尼克号幸存分析（字段介绍）

参考：Red and White Wine Quality