Python csv编写器截断数字格式

我正在打印带有标题的数组的内容。数组包含python以指数格式打印的非常小的数字。使用csv写入程序和标题在numpy行堆栈中打印时，指数会被截断。如果打印时没有标题，则显示指数

A版：

print t
[[  5.16535888e-06   4.38980952e+02]
[  1.34684766e-05   3.37237262e+02]
[  7.95903202e-06   6.45989985e+02]
[  8.35716563e-06   3.66632398e+02]
[  9.39419622e-06   7.14825200e+01]]

B版：

# print in table form
writer = csv.writer(sys.stdout, delimiter="\t")        
writer.writerows([komponents])
writer.writerows(np.row_stack((t)))
>>>
col1    col2
5.16535887883e-06   438.980952441
1.34684765805e-05   337.237261686
7.95903202041e-06   645.989985081
8.35716563314e-06   366.632397875
9.39419621582e-06   71.4825200296

C版：

# print in table form
writer = csv.writer(sys.stdout, delimiter="\t")    
writer.writerows(np.row_stack((komponents, t)))
>>>
col1    col2
5.165358    438.9809
1.346847    337.2372
7.959032    645.9899
8.357165    366.6323
9.394196    71.48252

显然，C版是不正确的

有什么想法吗？

---

谢谢

问题在于您正在强制浮点值的数据类型。调用时，数据类型将变为字符串。例如：

>>> x = numpy.array([1.34684766e-05, 6.45989985e+02])
>>> s = numpy.array(["col1", "col2"])
>>> numpy.row_stack((x,s))
array([['1.346847', '645.9899'],
       ['col1', 'col2']], 
      dtype='|S8')

>>> import numpy
>>> t = numpy.array([[  5.16535888e-06,   4.38980952e+02],
... [  1.34684766e-05,   3.37237262e+02],
... [  7.95903202e-06,   6.45989985e+02],
... [  8.35716563e-06,   3.66632398e+02],
... [  9.39419622e-06,   7.14825200e+01]])
>>> komponents = numpy.array([["col1", "col2"]])
>>>
>>> import StringIO
>>> s = StringIO.StringIO()
>>> numpy.savetxt(s, komponents, fmt="%s", delimiter="\t")
>>> numpy.savetxt(s, x, delimiter="\t")
>>> print s.getvalue()
col1    col2
5.165358879999999622e-06    4.389809520000000020e+02
1.346847660000000055e-05    3.372372619999999870e+02
7.959032020000000055e-06    6.459899850000000470e+02
8.357165630000000265e-06    3.666323980000000233e+02
9.394196219999999191e-06    7.148251999999999384e+01

我建议用这个。例如：

>>> x = numpy.array([1.34684766e-05, 6.45989985e+02])
>>> s = numpy.array(["col1", "col2"])
>>> numpy.row_stack((x,s))
array([['1.346847', '645.9899'],
       ['col1', 'col2']], 
      dtype='|S8')

>>> import numpy
>>> t = numpy.array([[  5.16535888e-06,   4.38980952e+02],
... [  1.34684766e-05,   3.37237262e+02],
... [  7.95903202e-06,   6.45989985e+02],
... [  8.35716563e-06,   3.66632398e+02],
... [  9.39419622e-06,   7.14825200e+01]])
>>> komponents = numpy.array([["col1", "col2"]])
>>>
>>> import StringIO
>>> s = StringIO.StringIO()
>>> numpy.savetxt(s, komponents, fmt="%s", delimiter="\t")
>>> numpy.savetxt(s, x, delimiter="\t")
>>> print s.getvalue()
col1    col2
5.165358879999999622e-06    4.389809520000000020e+02
1.346847660000000055e-05    3.372372619999999870e+02
7.959032020000000055e-06    6.459899850000000470e+02
8.357165630000000265e-06    3.666323980000000233e+02
9.394196219999999191e-06    7.148251999999999384e+01