这不是一个二维数组。它是一个一维数组,其元素是对象,在这种情况下是一些包含4个元素的列表和一个包含5个元素的列表。而这些列表包含字符串。
In [577]: np.array([['34.5500000', '36.9000000', '37.3200000', '37.6700000'],
...: ['41.7900000', '44.8000000', '48.2600000', '46.1800000'],
...: ['36.1200000', '37.1500000', '39.3100000', '38.1000000'],
...: ['82.1000000', '82.0900000', '76.0200000', '77.7000000'],
...: ['48.0100000', '51.2500000', '51.1700000', '52.5000000', '55.25
...: 00000'],
...: ['39.7500000', '39.5000000', '36.8100000', '37.2500000']], dtyp
...: e=object)
Out[577]:
array([['34.5500000', '36.9000000', '37.3200000', '37.6700000'],
['41.7900000', '44.8000000', '48.2600000', '46.1800000'],
['36.1200000', '37.1500000', '39.3100000', '38.1000000'],
['82.1000000', '82.0900000', '76.0200000', '77.7000000'],
['48.0100000', '51.2500000', '51.1700000', '52.5000000', '55.2500000'],
['39.7500000', '39.5000000', '36.8100000', '37.2500000']], dtype=object)
In [578]: MyArray=_
In [579]: MyArray.shape
Out[579]: (6,)
In [580]: MyArray[0]
Out[580]: ['34.5500000', '36.9000000', '37.3200000', '37.6700000']
In [581]: MyArray[5]
Out[581]: ['39.7500000', '39.5000000', '36.8100000', '37.2500000']
In [582]: MyArray[4]
Out[582]: ['48.0100000', '51.2500000', '51.1700000', '52.5000000', '55.2500000']
In [583]:
为了对其进行切片,您需要遍历数组的元素。
In [584]: [d[:4] for d in MyArray]
Out[584]:
[['34.5500000', '36.9000000', '37.3200000', '37.6700000'],
['41.7900000', '44.8000000', '48.2600000', '46.1800000'],
['36.1200000', '37.1500000', '39.3100000', '38.1000000'],
['82.1000000', '82.0900000', '76.0200000', '77.7000000'],
['48.0100000', '51.2500000', '51.1700000', '52.5000000'],
['39.7500000', '39.5000000', '36.8100000', '37.2500000']]
现在,由于所有子列表长度相同,
np.array
将创建一个二维数组:
In [585]: np.array(_)
Out[585]:
array([['34.5500000', '36.9000000', '37.3200000', '37.6700000'],
['41.7900000', '44.8000000', '48.2600000', '46.1800000'],
['36.1200000', '37.1500000', '39.3100000', '38.1000000'],
['82.1000000', '82.0900000', '76.0200000', '77.7000000'],
['48.0100000', '51.2500000', '51.1700000', '52.5000000'],
['39.7500000', '39.5000000', '36.8100000', '37.2500000']],
dtype='<U10')
还是字符串,不过
In [586]: np.array(__,dtype=float)
Out[586]:
array([[ 34.55, 36.9 , 37.32, 37.67],
[ 41.79, 44.8 , 48.26, 46.18],
[ 36.12, 37.15, 39.31, 38.1 ],
[ 82.1 , 82.09, 76.02, 77.7 ],
[ 48.01, 51.25, 51.17, 52.5 ],
[ 39.75, 39.5 , 36.81, 37.25]])
MyArray.shape
? - hpauljnp.array
并没有被实现为列表的列表。显示效果看起来是这样的,但在内部numpy
并不是这样工作的。但在这种情况下,您确实有一个列表数组。 - hpaulj