jupyter_机器学习基础

import pandas as pd
import numpy as np

pd.DataFrame(np.random.randn(2,3))



score=np.random.randint(40,100,(10,5))
score


score_df=pd.DataFrame(score)

score_df

subjects=['语文','数学','英语','体育','政治']
stu=['同学'+str(i) for i in range(score_df.shape[0])]
data=pd.DataFrame(score,index=stu,columns=subjects)


data

data.head(5)

data_T=data.T
data_T


# 重设索引

stu=['同学_'+str(i) for i in range(score_df.shape[0])]
data.index=stu
data

import pandas as pd

datas=pd.read_csv('./data/tianchi_mum_baby.csv')
datas

datas.iloc[2:4,0:3]

datas['birthday'][1]#padans里索引操作先列后行

# 赋值操作

datas['user_id']=1
datas.head(5)

## 排序操作

datas.sort_values(by='birthday',ascending=False).head(5)

datas.sort_index().head(5)