error -> bias, variance

a more complex model does not always lead to better performance on testing data

main pandas methods

pandas is used to load, process, analyze
data structure: series anda dataframe class

locate

pd.loc[row, col]
pd.iloc[row, col] must be number as input

SQL exercise from leetcode Database category at level of Easy and Medium

SELECT * FROM item_mast
WHERE pro_price BETWEEN 200 AND 600; [include 200 and 600]

1. Data integrity

• validity and accuracy of data, maintain health of database

在excel里使用的函数

平均数 - AVERAGE(数值范围)
总和 - SUM(数值范围)

docker client(cli) <- command

html5

• 在html上作出新的特性，加入canvas，媒介回放的video和audio元素，对离线储存更好地支持，新的特殊内容元素，和新的表单控件(calendar、date、time、email、url、search)

Ribbon tabs - Insert

交叉分析筛选器Slicer

• Insert里有Slicer 选择field 可多项选择 最后会将选的field单独做成小表