pandas之索引、选取和过滤

obj=Series(np.arange(4.),index=['a','b','c','d'])
from pandas import *
import pandas as pd
obj=Series(np.arange(4.),index=['a','b','c','d'])
obj
obj['b']
obj[1]
obj[2:4]
obj[['b','a','d']]
obj
obj[[1,3]]
obj[obj<2]
obj['b':'c']
obj['b':'c']=5
obj
data=DataFrame(np.arange(16).reshape((4,4)),index=['Ohio','Colorado','Utah','New York'],columns=['one','two','three','four'])
data
data['two']
data['three','one']
data[['three','one']]
data
data[:2]
data[data['three']>5]
data<5
data[data<5]=0
data
data.ix['Colarado',['two','three']]
data.ix['Colorado',['two','three']]
data.ix['Colorado',[3,0,1]]
data
data.ix[2]
data.ix[:'Utah','two']
data
data.ix[data.three>5,:3]