从python中的numpy genfromtxt获取列名

从python中的numpy genfromtxt获取列名,python,numpy,genfromtxt,Python,Numpy,Genfromtxt,在python中使用numpy genfromtxt,我希望能够获取列标题作为给定数据的键。我尝试了以下方法,但无法获得相应数据的列名 column = np.genfromtxt(pathToFile,dtype=str,delimiter=',',usecols=(0)) columnData = np.genfromtxt(pathToFile,dtype=str,delimiter=',') data = dict(zip(column,columnData.tolist())) 下面

在python中使用numpy genfromtxt,我希望能够获取列标题作为给定数据的键。我尝试了以下方法,但无法获得相应数据的列名

column = np.genfromtxt(pathToFile,dtype=str,delimiter=',',usecols=(0))
columnData = np.genfromtxt(pathToFile,dtype=str,delimiter=',')
data = dict(zip(column,columnData.tolist()))
下面是数据文件

header0,header1,header2
mydate,3.4,2.0
nextdate,4,6
afterthat,7,8
目前,它将数据显示为

{
  "mydate": [
    "mydate",
    "3.4",
    "2.0"
  ],
  "nextdate": [
    "nextdate",
    "4",
    "6"
  ],
  "afterthat": [
    "afterthat",
    "7",
    "8"
  ]
}
我想用这种格式

{
  "mydate": {
    "header1":"3.4",
    "header2":"2.0"
  },
  "nextdate": {
    "header1":"4",
    "header2":"6"
  },
  "afterthat": {
   "header1":"7",
   "header2":  "8"
  }
}
有什么建议吗?

使用熊猫模块:

In [94]: fn = r'D:\temp\.data\z.csv'
将CSV读入数据框:

In [95]: df = pd.read_csv(fn)

In [96]: df
Out[96]:
     header0  header1  header2
0     mydate      3.4      2.0
1   nextdate      4.0      6.0
2  afterthat      7.0      8.0
获取所需的dict:

In [97]: df.set_index('header0').to_dict('index')
Out[97]:
{'afterthat': {'header1': 7.0, 'header2': 8.0},
 'mydate': {'header1': 3.3999999999999999, 'header2': 2.0},
 'nextdate': {'header1': 4.0, 'header2': 6.0}}
或作为JSON字符串:

In [107]: df.set_index('header0').to_json(orient='index')
Out[107]: '{"mydate":{"header1":3.4,"header2":2.0},"nextdate":{"header1":4.0,"header2":6.0},"afterthat":{"header1":7.0,"header2":8.0}}'

通过示例文件和
genfromtxt
调用,我得到了两个数组:

In [89]: column
Out[89]: 
array(['header0', 'mydate', 'nextdate', 'afterthat'], 
      dtype='<U9')
In [90]: columnData
Out[90]: 
array([['header0', 'header1', 'header2'],
       ['mydate', '3.4', '2.0'],
       ['nextdate', '4', '6'],
       ['afterthat', '7', '8']], 
      dtype='<U9')
现在构建一个字典字典(我不需要单独的
数组):

稍微细化一下:

In [95]: {row[0]: {h:v for h,v in zip(headers[1:], row[1:])} for row in columnData[1:]}
Out[95]: 
{'afterthat': {'header1': '7', 'header2': '8'},
 'mydate': {'header1': '3.4', 'header2': '2.0'},
 'nextdate': {'header1': '4', 'header2': '6'}}
我喜欢字典的理解

您的列表词典版本:

In [100]: {row[0]:row[1:] for row in columnData[1:].tolist()}
Out[100]: {'afterthat': ['7', '8'], 'mydate': ['3.4', '2.0'], 'nextdate': ['4', '6']}

你考虑过吗?为什么是3.39999999999999???@RAVI,它是
4.0
;)的python/pandas表示形式为什么只有3.4->3.399999999999而没有任何其他值,如2.0->1.9999999999999??同样在to_json输出中,它正确地得到了3.4。拉维,我不知道python/pandas什么时候决定以不同的方式表示浮动。但您可以通过以下示例查看它
print(0.1+0.2)
。顺便说一句:
df.to_dict('index')
正确显示浮动…这对numpy非常有效。非常感谢你。我不能使用熊猫,因为在我的情况下,新装置是非常有选择性的,除非有适当的理由。
In [95]: {row[0]: {h:v for h,v in zip(headers[1:], row[1:])} for row in columnData[1:]}
Out[95]: 
{'afterthat': {'header1': '7', 'header2': '8'},
 'mydate': {'header1': '3.4', 'header2': '2.0'},
 'nextdate': {'header1': '4', 'header2': '6'}}
In [100]: {row[0]:row[1:] for row in columnData[1:].tolist()}
Out[100]: {'afterthat': ['7', '8'], 'mydate': ['3.4', '2.0'], 'nextdate': ['4', '6']}