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📜  numpy recarray.tobytes()函数| Python

📅  最后修改于: 2022-05-13 01:54:48.279000             🧑  作者: Mango

numpy recarray.tobytes()函数| Python

在 numpy 中，数组可能具有包含字段的数据类型，类似于电子表格中的列。一个例子是[(a, int), (b, float)] ，其中数组中的每个条目都是一对 (int, float)。通常，使用诸如arr['a'] and arr['b']类的字典查找来访问这些属性。

记录数组允许使用arr.a and arr.b作为数组成员访问字段。 numpy.recarray.tobytes()函数构造包含数组中原始数据字节的Python字节。

代码#1： 

# Python program explaining
# numpy.recarray.tobytes() method 
  
# importing numpy as geek
import numpy as geek
  
# creating input array with 2 different field 
in_arr = geek.array([[(5.0, 2), (3.0, -4), (6.0, 9)],
                     [(9.0, 1), (5.0, 4), (-12.0, -7)]],
                     dtype =[('a', float), ('b', int)])
  
print ("Input array : ", in_arr)
  
# convert it to a record array,
# using arr.view(np.recarray)
rec_arr = in_arr.view(geek.recarray)
print("Record array of float: ", rec_arr.a)
print("Record array of int: ", rec_arr.b)
  
# applying recarray.tobytes methods
# to float record array in default order
out_arr = rec_arr.a.tobytes()
print ("Output Python bytes of float record array in default order ", out_arr) 
print()
  
# applying recarray.tobytes methods
# to float record array in fortan order
out_arr = rec_arr.a.tobytes(order ='F')
print ("Output Python bytes of float record array in fortan order ", out_arr) 
print()
  
# applying recarray.tobytes methods 
# to int record array in default order
out_arr = rec_arr.b.tobytes()
print ("Output Python bytes of int record array in default order ", out_arr) 
print()
  
# applying recarray.tobytes methods 
# to int record array in fortan order
out_arr = rec_arr.b.tobytes(order ='F')
print ("Output Python bytes of int record array in fortan order ", out_arr) 
输出：

代码#2：

我们将numpy.recarray.tobytes()应用于整个记录数组。 

# Python program explaining
# numpy.recarray.tobytes() method 
  
# importing numpy as geek
import numpy as geek
  
# creating input array with 2 different field 
in_arr = geek.array([[(5.0, 2), (3.0, 4), (6.0, -7)],
                     [(9.0, 1), (6.0, 4), (-2.0, -7)]],
                     dtype =[('a', float), ('b', int)])
  
print ("Input array : ", in_arr)
  
# convert it to a record array, 
# using arr.view(np.recarray)
rec_arr = in_arr.view(geek.recarray)
  
# applying recarray.tobytes methods to  
# record array in default order
out_arr = rec_arr.tobytes()
print ("Output Python bytes of record array in default order ", out_arr) 
print()
  
# applying recarray.tobytes methods to  
# record array in fortan order
out_arr = rec_arr.tobytes(order ='F')
print ("Output Python bytes of record array in fortan order ", out_arr) 
输出：