import numpy as np

np.set_printoptions(threshold=np.nan)
print(ndarray)

set_printoptions(precision=None, 
   threshold=None, 
   edgeitems=None,
   linewidth=None, 
   suppress=None,
   nanstr=None,
   infstr=None,
   formatter=None)

precision:

 np.set_printoptions(precision=4)
 print(np.array([1.23456789]))
  [ 1.2346] # 最后进位了

threshold:

 np.set_printoptions(threshold=10)
 print(np.arange(1, 11, 1)) # np.arange(1, 11, 1)生成出来是[1-10],10个数
  [ 1 2 3 4 5 6 7 8 9 10]

 np.set_printoptions(threshold=9)
 print(np.arange(1, 11, 1))
  [ 1 2 3 ..., 8 9 10]

edgeitems:

 np.set_printoptions(threshold=5)
 print(np.arange(1, 11, 1))
  [ 1 2 3 ..., 8 9 10]

 np.set_printoptions(threshold=5, edgeitems=4)
 print(np.arange(1, 11, 1))
  [ 1 2 3 4 ..., 7 8 9 10]

formatter

 np.set_printoptions(formatter={'all': lambda x: 'int: ' + str(-x)})
 print(np.arange(1, 5, 1))
  [int: -1 int: -2 int: -3 int: -4]