NumPy IO

numpy.save(file, arr, allow_pickle=True, fix_imports=True)

import numpy as np 

a = np.array([1,2,3,4,5]) 

# 保存到 outfile.npy 文件上
np.save('outfile.npy',a) 

# 保存到 outfile2.npy 文件上，如果文件路径末尾没有扩展名 .npy，该扩展名会被自动加上
np.save('outfile2',a)

$ cat outfile.npy 
?NUMPYv{'descr': '<i8', 'fortran_order': False, 'shape': (5,), }  
$ cat outfile2.npy 
?NUMPYv{'descr': '<i8', 'fortran_order': False, 'shape': (5,), } 

import numpy as np 

b = np.load('outfile.npy')  
print (b)

[1 2 3 4 5]

numpy.savez(file, *args, **kwds)

import numpy as np 

a = np.array([[1,2,3],[4,5,6]])
b = np.arange(0, 1.0, 0.1)
c = np.sin(b)
# c 使用了关键字参数 sin_array
np.savez("geek-docs.npz", a, b, sin_array = c)
r = np.load("geek-docs.npz")
print(r.files) # 查看各个数组名称
print(r["arr_0"]) # 数组 a
print(r["arr_1"]) # 数组 b
print(r["sin_array"]) # 数组 c

['sin_array', 'arr_0', 'arr_1']
[[1 2 3]
 [4 5 6]]
[0.  0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9]
[0.         0.09983342 0.19866933 0.29552021 0.38941834 0.47942554
 0.56464247 0.64421769 0.71735609 0.78332691]

np.loadtxt(FILENAME, dtype=int, delimiter=' ')
np.savetxt(FILENAME, a, fmt="%d", delimiter=",")

import numpy as np 

a = np.array([1,2,3,4,5])
np.savetxt('out.txt',a)
b = np.loadtxt('out.txt')

print(b)

[1. 2. 3. 4. 5.]

import numpy as np 


a=np.arange(0,10,0.5).reshape(4,-1)
np.savetxt("out.txt",a,fmt="%d",delimiter=",") # 改为保存为整数，以逗号分隔
b = np.loadtxt("out.txt",delimiter=",") # load 时也要指定为逗号分隔
print(b)

[[0. 0. 1. 1. 2.]
 [2. 3. 3. 4. 4.]
 [5. 5. 6. 6. 7.]
 [7. 8. 8. 9. 9.]]