#  自定义结构数组
import numpy as np
persontype = np.dtype({'names':['name', 'age', 'chinese', 'math', 'english']#自定义命名空间, 
                            ,'formats':['U32','i', 'i', 'i', 'f']})
peoples = np.array([("ZhangFei",32,75,100, 90),("GuanYu",24,85,96,88.5), 
                        ("ZhaoYun",28,85,92,96.5),("HuangZhong",29,65,85,100)], dtype=persontype)
ages = peoples['age']
chineses = peoples['chinese']
maths = peoples['math']
englishs = peoples['english']
print(np.mean(ages))
print(np.mean(chineses))
print(np.mean(maths))
print(np.mean(englishs))
print(peoples['name'])
print(ages)
print(chineses)
print(maths)
print(englishs)
print(peoples)
print(peoples[0][1:])#不支持 此种切片索引因为数组是peoples是一维的

28.25
77.5
93.25
93.75
['ZhangFei' 'GuanYu' 'ZhaoYun' 'HuangZhong']
[32 24 28 29]
[75 85 85 65]
[100  96  92  85]
[ 90.   88.5  96.5 100. ]
[('ZhangFei', 32, 75, 100,  90. ) ('GuanYu', 24, 85,  96,  88.5)
 ('ZhaoYun', 28, 85,  92,  96.5) ('HuangZhong', 29, 65,  85, 100. )]



---------------------------------------------------------------------------

IndexError                                Traceback (most recent call last)

<ipython-input-98-30558e3ef830> in <module>
     19 print(englishs)
     20 print(peoples)
---> 21 print(peoples[0][1:])#不支持 此种切片索引因为数组是peoples是一维的


IndexError: too many indices for array

Meanlist = []
for i  in range(peoples.size):
    a = np.mean(list(peoples[i])[1:])
    Meanlist.append((peoples[i][0],a))
print(Meanlist)
print(sorted(Meanlist,key=lambda x:x[1]))

[(b'ZhangFei', 74.25), (b'GuanYu', 73.375), (b'ZhaoYun', 75.375), (b'HuangZhong', 69.75)]
[(b'HuangZhong', 69.75), (b'GuanYu', 73.375), (b'ZhangFei', 74.25), (b'ZhaoYun', 75.375)]

#自定义数据类型
#下面的代码格式不对
dt = np.dtype([[s32,i,i,i,f]])
hero = np.array([["ZhangFei",32,75,100, 90],["GuanYu",24,85,96,88.5], 
                     ["ZhaoYun",28,85,92,96.5],["HuangZhong",29,65,85,100]],dtype=dt)
print(hero)

---------------------------------------------------------------------------

NameError                                 Traceback (most recent call last)

<ipython-input-55-7dd6262c0288> in <module>
      1 #自定义数据类型
----> 2 dt = np.dtype([[s32,i,i,i,f]])
      3 hero = np.array([["ZhangFei",32,75,100, 90],["GuanYu",24,85,96,88.5], 
      4                      ["ZhaoYun",28,85,92,96.5],["HuangZhong",29,65,85,100]],dtype=dt)
      5 print(hero)


NameError: name 's32' is not defined

print(Meanlist)
Meanlist.sort(key = lambda x:x[1],reverse=True)
print(Meanlist)

[(b'HuangZhong', 69.75), (b'GuanYu', 73.375), (b'ZhangFei', 74.25), (b'ZhaoYun', 75.375)]
[(b'ZhaoYun', 75.375), (b'ZhangFei', 74.25), (b'GuanYu', 73.375), (b'HuangZhong', 69.75)]

print(peoples)

[(b'ZhangFei', 32, 75, 100,  90. ) (b'GuanYu', 24, 85,  96,  88.5)
 (b'ZhaoYun', 28, 85,  92,  96.5) (b'HuangZhong', 29, 65,  85, 100. )]

print(peoples['math'].argmax())
print('数学最高分是',peoples[peoples['math'].argmax()][0],peoples['math'].max(),'分')

0
数学最高分是 ZhangFei 100 分

github代码地址

https://github.com/luozekun1230/MyPyhonProgram/tree/master/Python%E5%9F%BA%E7%A1%80