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原创 SQL常用知识

1.替换对应字段中内容replace(TB1.Zy,' ','') as JJ 2.截取字段subString(BNum,1,2)，subString(BNum,3,2)3.类型转换convert(varchar(50),'-')，convert(varchar(50),'20')4.判断字段内容是否为空S.BNum is null or S.BNum=''5.条件...

2018-07-30 16:35:04 257

原创如何显示Python IDLE Shell的历史命令(Alt+P,Alt+N)

Alt+PAlt+N可以在IDLE中设置：Options->Configure IDLE->Keys->Action-key(s)

2018-05-30 16:52:14 6355 1

原创机器学习笔记(lightgbm)：OSError: [WinError 126] 找不到指定的模块

import lightgbm as lgb File "D:\Python\Python36-32\lib\site-packages\lightgbm\__init__.py", line 8, in <module> from .basic import Booster, Dataset File "D:\Python\Python36-32\lib\site-...

2018-05-05 14:06:16 5699

原创《机器学习实战》笔记-第8章：矩阵中.T及.I的区别

参照程序清单8-2操作时，错误的把“.I”写成了“.T”,导致最终结果完全不对。#程序清单8-2 局部加权线性回归函数 20180424def lwlr(testPoint,xArr,yArr,k=1.0): xMat = mat(xArr);yMat = mat(yArr).T m =shape(xMat)[0] weights = mat(eye((m))) #创建对...

2018-04-24 16:39:09 2360

原创《机器学习实战》笔记：第8章，ValueError: x and y must be the same size

>>> yMat = xMat*ws>>> import matplotlib.pyplot as plt>>> fig =plt.figure()>>> ax =fig.add_subplot(111)>>> ax.scatter(xMat[:,1].flatten().A[0],yMat.T[:,

2018-04-24 13:01:32 28550

原创《机器学习实战》笔记：RuntimeWarning: overflow encountered in exp

>>> logRegres.multiTest()Warning (from warnings module): File "E:/AI/FirstPythonProj\logRegres.py", line 13 return 1.0/(1+exp(-inX))RuntimeWarning: overflow encountered in expthe error ra...

2018-04-12 16:15:13 22762 10

原创《机器学习实战》笔记：程序清单5-2 AttributeError: Unknown property maker

>>> imp.reload(logRegres)<module 'logRegres' from 'E:/AI/FirstPythonProj\\logRegres.py'>>>> logRegres.plotBestFit(wei)Traceback (most recent call last): File "<pyshell#30&g...

2018-04-11 21:25:46 3674

原创《机器学习实战》中贝叶斯分类导入RSS源中entries为[]

《机器学习实战》中贝叶斯分类中导入RSS源例子_python_动态网站制作指南 http://www.knowsky.com/885215.html参考原文： http://newyork.craigslist.org/stp/index.rss 替换为：NASA Image of the Day：http://www.nasa.gov/rss/dyn/image_of_the_day...

2018-04-08 20:34:20 2532

原创《机器学习实战》笔记：UnicodeDecodeError: 'gbk' codec can't decode byte 0xae in position 199: illegal multibyte

>>> bayes.spamTest()Traceback (most recent call last): File "<pyshell#19>", line 1, in <module> bayes.spamTest() File "E:\AI\FirstPythonProj\bayes.py", line 96, in spamTest ...

2018-04-06 23:04:26 5309 2

原创《机器学习实战》笔记：IndexError: list index out of range

>>> myTree =trees.createTree(myDat,label)Traceback (most recent call last): File "<pyshell#6>", line 1, in <module> myTree =trees.createTree(myDat,label) File "E:\AI\FirstPyt...

2018-04-01 11:31:25 2382 4

原创《机器学习实战》笔记：TypeError: unsupported operand type(s) for *: 'float' and 'NoneType'

def chooseBestFeatureToSplit(dataSet): numFeatures = len(dataSet[0]) - 1 baseEntropy = calcShannonEnt(dataSet) bestInfoGain = 0.0; bestFeature = -1 for i in range(numFeatures): ...

2018-03-31 18:41:08 45520 5

1.The print statement has been replaced with a print() function, with keyword arguments to replace most of the special syntax of the old printstatement (PEP 3105).2.dictFixes dictionary iteration meth...

2018-03-24 08:50:20 234

原创 Python IDLE 如何定位行号

Python IDLE 不显示行号，可通过 Alt+G 快速定位到目的行号。

2018-03-23 19:38:21 1728

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