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【机器学习手册】【2】熟悉sklearn,加载数据集,完整

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【机器学习手册】【2】熟悉sklearn,加载数据集,完整

前言

这篇依然没有涉及什么高深的原理,仅仅是上手练习的一些东西。


加载样本
import numpy as np
from scipy import sparse
from sklearn import datasets



#加载手写数字的数据集
digits_set = datasets.load_digits()

#创建特征矩阵
features_matrix = digits_set.data

#创建目标向量
target_vector = digits_set.target

#查看第一个样本
print(features_matrix[0])
print(features_matrix[0].size)
print(features_matrix)
print(features_matrix.shape[0])
print(features_matrix.shape[1])
[ 0.  0.  5. 13.  9.  1.  0.  0.  0.  0. 13. 15. 10. 15.  5.  0.  0.  3.
 15.  2.  0. 11.  8.  0.  0.  4. 12.  0.  0.  8.  8.  0.  0.  5.  8.  0.
  0.  9.  8.  0.  0.  4. 11.  0.  1. 12.  7.  0.  0.  2. 14.  5. 10. 12.
  0.  0.  0.  0.  6. 13. 10.  0.  0.  0.]
64
[[ 0.  0.  5. ...  0.  0.  0.]
 [ 0.  0.  0. ... 10.  0.  0.]
 [ 0.  0.  0. ... 16.  9.  0.]
 ...
 [ 0.  0.  1. ...  6.  0.  0.]
 [ 0.  0.  2. ... 12.  0.  0.]
 [ 0.  0. 10. ... 12.  1.  0.]]
1797
64
创建仿真数据 make_regression用作线性回归
from sklearn.datasets import make_regression

#特征就是变量x
#生成特征矩阵,目标向量,模型的系数
feature_matrix,target_vector,model_coefficent = make_regression(n_samples=30,          #样本数
                                                                n_features=3,          #特征数,也就是变量个数
                                                                n_informative=3,       #参与建模的特征数
                                                                n_targets=1,           #因变量个数
                                                                noise=0,               #噪声
                                                                coef=True,             #是否输出coef标志
                                                                random_state=1)        #固定值表示每次调用参数一样的数据

#所有特征矩阵
print('Feature Matrix')
print(feature_matrix)
print('--------------------------------')
print(feature_matrix[:3])

#所有目标向量
print('Target Vector')
print(target_vector)
print('--------------------------------')
print(target_vector[:3])

#所有系数
print('Model Coefficient')
print(model_coefficent)
Feature Matrix
[[-1.10061918  0.58281521  0.04221375]
 [ 2.10025514  0.19091548 -0.63699565]
 [ 0.88514116  0.28558733  0.93110208]
 [ 0.53035547 -0.26788808 -0.93576943]
 [-0.50446586 -1.44411381 -1.39649634]
 [-0.87785842 -0.17242821 -1.09989127]
 [ 1.13376944 -0.38405435 -0.3224172 ]
 [-0.07557171  0.48851815 -0.29809284]
 [-0.34934272 -1.1425182  -0.35224985]
 [-0.22232814  0.76201118  0.23009474]
 [-0.12289023 -0.68372786  0.90085595]
 [ 1.12948391  0.12182127  0.37756379]
 [ 0.83898341  0.58662319 -0.20889423]
 [ 0.50249434  0.90159072  1.14472371]
 [ 1.65980218  0.2344157  -1.11731035]
 [-0.67066229  0.11900865  0.19829972]
 [ 2.18557541  1.51981682  1.13162939]
 [ 0.30017032  0.61720311  0.12015895]
 [ 0.82797464 -0.30620401 -2.02220122]
 [-2.3015387   0.86540763 -1.07296862]
 [ 0.41005165  0.18656139 -0.20075807]
 [-0.0126646  -0.67124613 -0.84520564]
 [-0.52817175 -0.61175641  1.62434536]
 [ 0.31563495  0.87616892  0.16003707]
 [ 0.05080775  1.6924546  -0.74715829]
 [ 0.3190391  -0.7612069   1.74481176]
 [ 0.51292982  1.25286816 -0.75439794]
 [-2.06014071  1.46210794 -0.24937038]
 [-0.88762896 -0.19183555  0.74204416]
 [-0.6871727  -0.39675353 -0.69166075]]
--------------------------------
[[-1.10061918  0.58281521  0.04221375]
 [ 2.10025514  0.19091548 -0.63699565]
 [ 0.88514116  0.28558733  0.93110208]]
Target Vector
[  37.74175696    6.94071851   86.5117958   -67.70279525 -205.06435022
  -86.22405342  -36.08410374   23.71711098 -120.01461189   74.12311585
   -9.29666977   45.15545942   48.26528776  145.43920532  -21.41853197
   12.65550405  217.67124509   62.34037388 -127.29381592  -15.02503683
    9.7024454  -103.40308389   31.72711817   86.54267457  101.8362499
   36.32267081   70.15981245   83.7468125    13.84670287  -80.17725038]
--------------------------------
[37.74175696  6.94071851 86.5117958 ]
Model Coefficient
[12.41733151 84.20308924 55.28219787]
make_classification用作分类
from sklearn.datasets import make_classification
#生成特征矩阵和目标向量
feature_matrix,target_vector = make_classification(n_samples=30,        #样本数
                                                   n_features=3,        #特征数
                                                   n_informative=3,     #参与建模的特征数
                                                   n_redundant=0,       #冗余信息
                                                   n_classes=2,         #类别
                                                   weights=[.25,.75],   #权重
                                                   random_state=1)      #固定值表示每次调用参数一样的数据

print('Feature Matrix')
print(feature_matrix)

print('Target Vector')
print(target_vector)
Feature Matrix
[[ 6.92519795e-01  1.13852523e+00  3.08812106e-01]
 [ 3.88951614e-01  1.35195506e+00  8.45267453e-01]
 [-1.61239191e+00  3.84863206e+00 -1.48104647e+00]
 [-1.55155113e+00 -9.15242208e-01  1.87070202e+00]
 [-1.37094493e+00  1.69611288e+00 -2.48345110e-01]
 [ 3.35688592e-01 -1.48298550e+00 -1.33301281e+00]
 [-1.68433513e+00  3.32953976e-01 -2.33101004e+00]
 [ 1.69960192e+00  8.14466543e-01 -3.34700643e-01]
 [-1.61123255e+00  1.25663465e+00 -1.88306830e+00]
 [-2.41080203e+00  5.44220286e-01 -1.13809428e+00]
 [-1.31576718e+00 -2.31329364e-01 -1.13715401e+00]
 [ 2.44352863e-01  1.10054314e+00 -1.52949645e+00]
 [-5.43585663e-01 -1.65153944e-01 -1.92898725e+00]
 [ 6.03050835e-01  1.73597889e+00  3.01950504e-01]
 [-1.49173629e-02  1.49493030e+00 -2.09226227e+00]
 [ 5.02745823e-01 -1.10378957e+00 -1.92250524e+00]
 [ 2.71333714e+00  1.29796309e+00 -5.74452615e-01]
 [ 1.21648685e+00  1.13814022e+00 -1.15907489e+00]
 [ 1.65879465e+00  3.09560595e+00  5.38155725e-01]
 [ 2.05191840e+00  2.03163207e+00 -4.45435701e-01]
 [-5.27732874e-01  2.35754111e+00 -7.01354054e-01]
 [ 6.50085392e-03 -2.79111057e+00  1.11765731e+00]
 [ 7.54879885e-01  1.44517982e+00 -1.06112098e+00]
 [-1.37185725e+00 -1.25387234e+00  2.01388876e+00]
 [ 1.60935053e+00  2.32646578e+00 -1.16622915e+00]
 [ 5.75450411e-01  2.01897401e-03 -7.14120297e-01]
 [-4.82268742e-01  2.99152002e+00 -1.56940995e+00]
 [-1.76396658e+00  5.39206733e-02 -5.59453249e-01]
 [-9.66653664e-01  2.45921914e+00 -8.49076661e-01]
 [-1.10692641e+00  1.18622109e+00 -1.34893436e+00]]
Target Vector
[0 0 1 0 1 1 1 1 1 1 1 1 1 0 1 1 1 1 0 1 1 0 1 0 1 1 1 1 1 1]
make_blobs用作聚类
from sklearn.datasets import make_blobs
#生成特征矩阵和目标向量
feature_matrix,target_vector = make_blobs(n_samples=30,        #样本数
                                          n_features=3,        #特征数
                                          centers=3,           #类别
                                          cluster_std=0.5,     #每个类的方差
                                          shuffle=True,        #洗乱数据
                                          random_state=1)      #固定值表示每次调用参数一样的数据

print('Feature Matrix')
print(feature_matrix)

print('Target Vector')
print(target_vector)

import matplotlib.pyplot as plt
#第一列第二列
plt.scatter(feature_matrix[:,0],feature_matrix[:,1],c = target_vector)
plt.show()

Feature Matrix
[[ -1.58030246   4.84319899 -10.05340419]
 [ -2.08458609   4.88689987 -10.10642159]
 [ -1.49416134   4.97746113 -10.56251008]
 [ -1.33141787   4.37524407 -10.86703965]
 [ -6.11226706  -3.19474192  -2.83801255]
 [ -6.26823132  -2.98766593  -1.83717439]
 [ -5.86852818  -2.98333444  -1.85376094]
 [ -4.5991299   -7.48900414  -8.23652789]
 [ -3.10743548  -7.43885905  -8.44362672]
 [ -5.75219546  -2.58359772  -2.02923219]
 [ -1.39265445   4.36050322  -9.04080231]
 [ -3.86138326  -7.27293797  -7.52820308]
 [ -3.77991888  -6.38136583  -7.81637007]
 [ -5.91600086  -3.21413791  -2.09041548]
 [ -4.00872553  -6.04386781  -7.92946776]
 [ -2.17857929   3.90174996 -10.52684078]
 [ -3.90176705  -7.37571561  -8.01536908]
 [ -6.47442986  -2.99825175  -1.66090654]
 [ -3.32919865  -7.44371925  -7.85908102]
 [ -3.49475054  -7.02475689  -8.03910872]
 [ -6.71503417  -2.94972104  -2.0997289 ]
 [ -5.43054725  -2.77587972  -2.87033242]
 [ -1.340879     3.97653657  -9.11140869]
 [ -5.96000181  -3.99549724  -1.29092623]
 [ -1.94281502   4.77147767  -9.81121561]
 [ -4.49868599  -7.36987481  -8.00002191]
 [ -2.84129421   4.97416254 -10.50621957]
 [ -5.98383318  -3.29388922  -0.91621746]
 [ -3.61165643  -7.0534392   -7.72461097]
 [ -2.21474143   4.497097    -9.71554007]]
Target Vector
[0 0 0 0 2 2 2 1 1 2 0 1 1 2 1 0 1 2 1 1 2 2 0 2 0 1 0 2 1 0]

Process finished with exit code 0

从普通文件中加载数据 csv
import pandas as pd

dataset = pd.read_csv('test.csv')
#前8行数据
print(dataset.head(8))
   5  2021-01-01 00:00:00  0
0  4  2021-01-01 00:00:01  1
1  3  2021-01-01 00:00:02  1
2  2  2021-01-01 00:00:03  0
3  1  2021-01-01 00:00:04  0

test.csv文件内容

5,2021-01-01 00:00:00,0
4,2021-01-01 00:00:01,1
3,2021-01-01 00:00:02,1
2,2021-01-01 00:00:03,0
1,2021-01-01 00:00:04,0
excel
import pandas as pd

dataframe = pd.read_excel('test.xls')
#前10行
print(dataframe.head(10))

没对齐

    姓名     年龄   电话  住址    忌日
0  100      0   20   3  NONE
1   99      0   21   3   YES
2   98    -10   23   3  NONE
3   96   -100  245   3   NIL
4   95  -1000   12   3    OL
5   94 -10000    4  33    OK

json
import pandas as pd

dataset = pd.read_json('_test.json')
print(dataset.head(10))
  version                                     configurations
0   0.2.0  {'type': 'chrome', 'request': 'launch', 'name'...

json格式化网站
http://www.kjson.com/

json文件

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "chrome",
            "request": "launch",
            "name": "Launch Chrome against localhost",
            "url": "file:///C:/Users/LX/Desktop/Code/JSLearning/module.html",
            "webRoot": "${workspaceRoot}"
        }
    ]
}
sqlite
import pandas as pd
import sqlite3

#连接或创建数据库
connection = sqlite3.connect('my_database.db')

#获取光标
cursor = connection.cursor()

#创建表
cursor.execute('CREATE TABLE demllie('
               'id varchar(20) primary key,'
               'name varchar(20)'
               ') ')

#插入数据
for i in range(10):
    cursor.execute('INSERT INTO demllie(id,name) values('
                   '%d,'%d SUATIN DEMLLIE ZHANGQI %d ''
                   ')'%(i,i,i))

#插入了多少行
print('row=',cursor.rowcount)

#查询表demllie
dataframe = pd.read_sql_query('SELECt * FROM demllie',connection)

#查看数据
print(dataframe.head(7))

#-------------

#关闭光标
cursor.close()

#关闭连接
connection.close()
row= 1
  id                         name
0  0  0 SUATIN DEMLLIE ZHANGQI 0 
1  1  1 SUATIN DEMLLIE ZHANGQI 1 
2  2  2 SUATIN DEMLLIE ZHANGQI 2 
3  3  3 SUATIN DEMLLIE ZHANGQI 3 
4  4  4 SUATIN DEMLLIE ZHANGQI 4 
5  5  5 SUATIN DEMLLIE ZHANGQI 5 
6  6  6 SUATIN DEMLLIE ZHANGQI 6 
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