Lab：使用决策树探索泰坦尼克号乘客存活情况

开始

在引导项目中，你研究了泰坦尼克号存活数据并能够对乘客存活情况作出预测。在该项目中，你手动构建了一个决策树，该决策树在每个阶段都会选择一个与存活情况最相关的特征。幸运的是，这正是决策树的运行原理！在此实验室中，我们将通过在 sklearn 中实现决策树使这一流程速度显著加快。

我们首先将加载数据集并显示某些行。



In [1]:

    
# Import libraries necessary for this project
import numpy as np
import pandas as pd
from IPython.display import display # Allows the use of display() for DataFrames

# Pretty display for notebooks
%matplotlib inline

# Set a random seed
import random
random.seed(42)

# Load the dataset
in_file = 'titanic_data.csv'
full_data = pd.read_csv(in_file)

# Print the first few entries of the RMS Titanic data
display(full_data.head())









    







  
    
      
      PassengerId
      Survived
      Pclass
      Name
      Sex
      Age
      SibSp
      Parch
      Ticket
      Fare
      Cabin
      Embarked
    
  
  
    
      0
      1
      0
      3
      Braund, Mr. Owen Harris
      male
      22.0
      1
      0
      A/5 21171
      7.2500
      NaN
      S
    
    
      1
      2
      1
      1
      Cumings, Mrs. John Bradley (Florence Briggs Th...
      female
      38.0
      1
      0
      PC 17599
      71.2833
      C85
      C
    
    
      2
      3
      1
      3
      Heikkinen, Miss. Laina
      female
      26.0
      0
      0
      STON/O2. 3101282
      7.9250
      NaN
      S
    
    
      3
      4
      1
      1
      Futrelle, Mrs. Jacques Heath (Lily May Peel)
      female
      35.0
      1
      0
      113803
      53.1000
      C123
      S
    
    
      4
      5
      0
      3
      Allen, Mr. William Henry
      male
      35.0
      0
      0
      373450
      8.0500
      NaN
      S

	PassengerId	Pclass	Name	Sex	Age	SibSp	Ticket	Fare	Cabin	Embarked
0	1	3	Braund, Mr. Owen Harris	male	22.0	1	A/5 21171	7.2500	NaN	S
1	2	1	Cumings, Mrs. John Bradley (Florence Briggs Th...	female	38.0	1	PC 17599	71.2833	C85	C
2	3	3	Heikkinen, Miss. Laina	female	26.0	0	STON/O2. 3101282	7.9250	NaN	S
3	4	1	Futrelle, Mrs. Jacques Heath (Lily May Peel)	female	35.0	1	113803	53.1000	C123	S
4	5	3	Allen, Mr. William Henry	male	35.0	0	373450	8.0500	NaN	S

	PassengerId	Pclass	Age	SibSp	Fare	...	Embarked_C	Embarked_S
0	1	3	22.0	1	7.2500	...	0	1
1	2	1	38.0	1	71.2833	...	1	0
2	3	3	26.0	0	7.9250	...	0	1
3	4	1	35.0	1	53.1000	...	0	1
4	5	3	35.0	0	8.0500	...	0	1

5 rows × 1730 columns