pandas模塊學習之創建序列和數據框

import numpy as np
import pandas as pd

# 序列的創建，總共三種方式

#(1)一維數組創建
arr = np.arange(10)
print(arr)
print(type(arr))

s1 = pd.Series(arr)
print(s1)
print(type(s1))
print(s1[1])

#(2)字典的方式創建

dic = {'a':10,'b':20,'c':30,'d':40,'e':50}
print(dic)
print(type(dic))
s2 = pd.Series(dic)
print(s2)
print(type(s2))


#通過DataFrame中的某一行或某一列創建序列（后續說）




#DateFrame的創建，三種方式

#(1)通過二維數組創建數據框

arr2 = np.array(np.arange(12)).reshape(4,3)
print(arr2)
print(type(arr2))

df = pd.DataFrame(arr2)
print(df)
print(type(df))


#(2)通過字典的方式創建數據框
dic1 = {'a':[1,2,3,4],'b':[5,6,7,8],'c':[9,10,11,12],'d':[13,14,15,16]}
print(dic1)
print(type(dic1))

df1=pd.DataFrame(dic1)
print(df1)
print(type(dic1))


#(3)通過嵌套字典的方式創建數據框
dic2={'a':{'a1':[1,2,3,4],'b':[5,6,7,8]},'b':{'a2':[2,3,4,5],'b2':[6,7,8,9]},'c':{'a3':[0,1,2,3],'b3':[0,7,6,5]}}
print(dic2)
print(type(dic2))
df2 = pd.DataFrame(dic2)
print(df2)
print(type(df2))

#(4)通過數據框的方式創建數據框

df3 = df2[['a','b']]
print(df3)
print(type(df3))