>>> import numpy as np>>> x = np.zeros(3, dtype=('i4',[('r','u1'), ('g','u1'), ('b','u1'), ('a','u1')]))>>> xTraceback (most recent call last):  File "<stdin>", line 1, in <module>  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 955, in array_repr    ', ', class_name + "(")  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 521, in array2string    lst = _array2string(a, options, separator, prefix)  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 363, in wrapper    return f(self, *args, **kwargs)  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 392, in _array2string    options['edgeitems'], summary_insert)[:-1]  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 565, in _formatArray    word = format_function(a[-i]) + separator  File "/Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py", line 886, in __call__    for field, format_function in zip(x, self.format_functions):TypeError: zip argument #1 must support iteration

>>> pdb.pm()> /Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py(886)__call__()-> for field, format_function in zip(x, self.format_functions):(Pdb) p x0(Pdb) u> /Users/tos/py3npy/lib/python3.6/site-packages/numpy-1.14.0.dev0+1f4ed32-py3.6-macosx-10.12-x86_64.egg/numpy/core/arrayprint.py(565)_formatArray()-> word = format_function(a[-i]) + separator(Pdb) p a.dtypedtype([('r', 'u1'), ('g', 'u1'), ('b', 'u1'), ('a', 'u1')])(Pdb) p a['r']array([0, 0, 0], dtype=uint8)(Pdb) p a[0]0