yu0046的博客

python 报错TypeError: 'in ’ requires string as left operand, not int原因：类型没对齐username = ‘root’tn.write(username + str(’\n’))就会报错应该改成tn.write(username.encode(‘ascii’) + str(’\n’))python3 中 文本字符串类型（unicode编码）被命名为str，字节字符串类型被命名为bytes，其中 str encode

VScode 安装python要安装插件和解释器，插件在VScode里面装，解释器在官网下载，然后启动解释器（activate 有一个python interpreter seletion）装插件的同时会自动装上 jupyter notebook用pip安装需要的包pip install numpy...

Data Vistualizationlibraries to plot:matplotlib (plt)pandas .plot()seaborn (sns)bar plotrug plots(easy to see distributions)histograms= bar + (areas represent proportions)​ default: show counts on y-axis.​ ‘density = True’ : the total areas sums

dataframe 更换列名# 更换列名，同时显示出来df.rename(columns={'a':'A'}, inplace=Ture)# 更换列名，不显示出来 inplace = False(默认)# 求取每一列（或某一列）的中位数，众数，均值，方差等df.groupby('key').aggregate(['min', np.median, max])# 把True/False写成1/0# 法1import numpy as npa = np.array([True, False