解决numpy 0d arrays error

使用numpy array时，可能会遇到 “iteration over a 0-d array” 的错误。

例1：

import numpy as np

a = 1
a = np.asarray(a)
for i in a:
  print(i)

TypeError: iteration over a 0-d array

例2:

import numpy as np

a, b = 1, 2
a, b = np.asarray(a), np.asarray(b)
for i, j in zip(a, b):
  print(i+j)

TypeError: zip argument #1 must support iteration

解决方法:

使用 numpy.atleast_1d() 即可：

import numpy as np

a, b = 1, 2
a, b = np.atleast_1d(a), np.atleast_1d(b)
for i, j in zip(a, b):
  print(i+j)

参考资料：Python, numpy; How to best deal with possible 0d arrays.