Question

大家好我有一个2d数组，我想创建一个只有2,3列的新2d数组

这是我的代码

#!/user
# -*- coding: utf-8 -*-

import csv
import urllib2
import numpy as np


url = 'https://api.bmreports.com/BMRS/FUELINST/v1?APIKey=66ky5jo5p5w0vbd&ServiceType=CSV'
url2 = 'https://api.bmreports.com/BMRS/FUELINSTHHCUR/v1?APIKey=66ky5jo5p5w0vbd&ServiceType=CSV'
response = urllib2.urlopen(url2)
cr = csv.reader(response)


arr = np.genfromtxt(response,delimiter=",", skip_header=1, skip_footer=2,dtype=None)

data = arr[:, [1:2]]


print data

所以数据会像这样回来

[('FUELINSTHHCUR', 'CCGT', 10430, 35.8, 10282, 35.2, 205996, 32. )
 ('FUELINSTHHCUR', 'OCGT',     0,  0. ,     0,  0. ,     17,  0. )
 ('FUELINSTHHCUR', 'OIL',     0,  0. ,     0,  0. ,      0,  0. )
 ('FUELINSTHHCUR', 'COAL',     0,  0. ,     0,  0. ,      0,  0. )
 ('FUELINSTHHCUR', 'NUCLEAR',  6963, 23.9,  6970, 23.9, 167591, 26. )
 ('FUELINSTHHCUR', 'WIND',  6986, 24. ,  7061, 24.2, 160036, 24.9)
 ('FUELINSTHHCUR', 'PS',   297,  1. ,   412,  1.4,   8136,  1.3)
 ('FUELINSTHHCUR', 'NPSHYD',   322,  1.1,   319,  1.1,   8015,  1.2)
 ('FUELINSTHHCUR', 'OTHER',   129,  0.4,   128,  0.4,   3093,  0.5)
 ('FUELINSTHHCUR', 'INTFR',  1494,  5.1,  1494,  5.1,  31731,  4.9)
 ('FUELINSTHHCUR', 'INTIRL',     0,  0. ,     0,  0. ,   2650,  0.4)
 ('FUELINSTHHCUR', 'INTNED',   882,  3. ,   880,  3. ,  18991,  2.9)
 ('FUELINSTHHCUR', 'INTEW',     0,  0. ,     0,  0. ,      0,  0. )
 ('FUELINSTHHCUR', 'BIOMASS',  1608,  5.5,  1630,  5.6,  37688,  5.9)]

我正在尝试创建一个新的2d数组，只返回列，所以它看起来像这样

[('CCGT', 10430)
 ('OCGT',     0)
 ('OIL',     0)
 ('COAL',     0)
 ('NUCLEAR',  6963)
 ('WIND',  6986)
 ('PS',   297)
 ('NPSHYD',   322)
 ('OTHER',   129)
 ('INTFR',  1494)
 ('INTIRL',     0)
 ('INTNED',   882)
 ('INTEW',     0)
 ('BIOMASS',  1608)]

Answer 1

首先，你需要使用Numpy数组来保存你的项而不是列表，然后你可以将列表中的列索引传递给第二个轴以获得所需的结果：

data = arr[:, [2, 3]]

或切片如下：

data = arr[:, 2:4]

此外，如果您正在阅读的字符串格式正确，而不是使用csv 你可以使用fromstring() 用于加载数据的功能。

Answer 2

如果您查看此代码示例，它可能会对您有所帮助。

它假设您收集的第一个值是numpy数组中的单个字符串....因此每行包含逗号和引用元素，但它们都嵌入在单个元素中。

var'lst'是一个列表，用于遍历所有数组元素并创建包含逗号分隔元素作为单个字符串的多维列表列表。

var'tmp'是一个由新解析的'lst'构成的numpy数组。

var'data'是来自'tmp'的切片numpy数组，只包含您要查找的列。

希望有帮助...


    import numpy as np

    def ElementSplit(x) : return x.split(",")
    ElementSplit = np.vectorize(ElementSplit)

    arr = np.array([["'FUELINSTHHCUR', 'CCGT', 10430, 35.8, 10282, 35.2, 205996, 32. "],
     ["'FUELINSTHHCUR', 'OCGT',     0,  0. ,     0,  0. ,     17,  0. "],
     [" 'FUELINSTHHCUR', 'OIL',     0,  0. ,     0,  0. ,      0,  0. "],
     [" 'FUELINSTHHCUR', 'COAL',     0,  0. ,     0,  0. ,      0,  0. "],
     [" 'FUELINSTHHCUR', 'NUCLEAR',  6963, 23.9,  6970, 23.9, 167591, 26. "],
     [" 'FUELINSTHHCUR', 'WIND',  6986, 24. ,  7061, 24.2, 160036, 24.9"],
     [" 'FUELINSTHHCUR', 'PS',   297,  1. ,   412,  1.4,   8136,  1.3"],
     [" 'FUELINSTHHCUR', 'NPSHYD',   322,  1.1,   319,  1.1,   8015,  1.2"],
     [" 'FUELINSTHHCUR', 'OTHER',   129,  0.4,   128,  0.4,   3093,  0.5"],
     [" 'FUELINSTHHCUR', 'INTFR',  1494,  5.1,  1494,  5.1,  31731,  4.9"],
     [" 'FUELINSTHHCUR', 'INTIRL',     0,  0. ,     0,  0. ,   2650,  0.4"],
     [" 'FUELINSTHHCUR', 'INTNED',   882,  3. ,   880,  3. ,  18991,  2.9"],
     [" 'FUELINSTHHCUR', 'INTEW',     0,  0. ,     0,  0. ,      0,  0. "],
     [" 'FUELINSTHHCUR', 'BIOMASS',  1608,  5.5,  1630,  5.6,  37688,  5.9"]])

    print " --arr--"
    print arr

    lst = []
    for items in arr:
        lst.append(items[0].split(", "))

    print " --lst--"
    print lst

    exit

    #data = arr[:]
    tmp = np.array(lst)

    print " --tmp--"
    print tmp

    data = tmp[:,[1,2]]

    print " --data--"
    print data

，输出看起来像这样......


    $python main.py
     --arr--
    [["'FUELINSTHHCUR', 'CCGT', 10430, 35.8, 10282, 35.2, 205996, 32. "]
     ["'FUELINSTHHCUR', 'OCGT',     0,  0. ,     0,  0. ,     17,  0. "]
     [" 'FUELINSTHHCUR', 'OIL',     0,  0. ,     0,  0. ,      0,  0. "]
     [" 'FUELINSTHHCUR', 'COAL',     0,  0. ,     0,  0. ,      0,  0. "]
     [" 'FUELINSTHHCUR', 'NUCLEAR',  6963, 23.9,  6970, 23.9, 167591, 26. "]
     [" 'FUELINSTHHCUR', 'WIND',  6986, 24. ,  7061, 24.2, 160036, 24.9"]
     [" 'FUELINSTHHCUR', 'PS',   297,  1. ,   412,  1.4,   8136,  1.3"]
     [" 'FUELINSTHHCUR', 'NPSHYD',   322,  1.1,   319,  1.1,   8015,  1.2"]
     [" 'FUELINSTHHCUR', 'OTHER',   129,  0.4,   128,  0.4,   3093,  0.5"]
     [" 'FUELINSTHHCUR', 'INTFR',  1494,  5.1,  1494,  5.1,  31731,  4.9"]
     [" 'FUELINSTHHCUR', 'INTIRL',     0,  0. ,     0,  0. ,   2650,  0.4"]
     [" 'FUELINSTHHCUR', 'INTNED',   882,  3. ,   880,  3. ,  18991,  2.9"]
     [" 'FUELINSTHHCUR', 'INTEW',     0,  0. ,     0,  0. ,      0,  0. "]
     [" 'FUELINSTHHCUR', 'BIOMASS',  1608,  5.5,  1630,  5.6,  37688,  5.9"]]
     --lst--
    [["'FUELINSTHHCUR'", "'CCGT'", '10430', '35.8', '10282', '35.2', '205996', '32. '], ["'FUELINSTHHCUR'", "'OCGT'", '    0', ' 0. ', '    0', ' 0. ', '    17', ' 0. '], [" 'FUELINSTHHCUR'", "'OIL'", '    0', ' 0. ', '    0', ' 0. ', '     0', ' 0. '], [" 'FUELINSTHHCUR'", "'COAL'", '    0', ' 0. ', '    0', ' 0. ', '     0', ' 0. '], [" 'FUELINSTHHCUR'", "'NUCLEAR'", ' 6963', '23.9', ' 6970', '23.9', '167591', '26. '], [" 'FUELINSTHHCUR'", "'WIND'", ' 6986', '24. ', ' 7061', '24.2', '160036', '24.9'], [" 'FUELINSTHHCUR'", "'PS'", '  297', ' 1. ', '  412', ' 1.4', '  8136', ' 1.3'], [" 'FUELINSTHHCUR'", "'NPSHYD'", '  322', ' 1.1', '  319', ' 1.1', '  8015', ' 1.2'], [" 'FUELINSTHHCUR'", "'OTHER'", '  129', ' 0.4', '  128', ' 0.4', '  3093', ' 0.5'], [" 'FUELINSTHHCUR'", "'INTFR'", ' 1494', ' 5.1', ' 1494', ' 5.1', ' 31731', ' 4.9'], [" 'FUELINSTHHCUR'", "'INTIRL'", '    0', ' 0. ', '    0', ' 0. ', '  2650', ' 0.4'], [" 'FUELINSTHHCUR'", "'INTNED'", '  882', ' 3. ', '  880', ' 3. ', ' 18991', ' 2.9'], [" 'FUELINSTHHCUR'", "'INTEW'", '    0', ' 0. ', '    0', ' 0. ', '     0', ' 0. '], [" 'FUELINSTHHCUR'", "'BIOMASS'", ' 1608', ' 5.5', ' 1630', ' 5.6', ' 37688', ' 5.9']]
     --tmp--
    [["'FUELINSTHHCUR'" "'CCGT'" '10430' '35.8' '10282' '35.2' '205996' '32. ']
     ["'FUELINSTHHCUR'" "'OCGT'" '    0' ' 0. ' '    0' ' 0. ' '    17' ' 0. ']
     [" 'FUELINSTHHCUR'" "'OIL'" '    0' ' 0. ' '    0' ' 0. ' '     0' ' 0. ']
     [" 'FUELINSTHHCUR'" "'COAL'" '    0' ' 0. ' '    0' ' 0. ' '     0' ' 0. ']
     [" 'FUELINSTHHCUR'" "'NUCLEAR'" ' 6963' '23.9' ' 6970' '23.9' '167591'
      '26. ']
     [" 'FUELINSTHHCUR'" "'WIND'" ' 6986' '24. ' ' 7061' '24.2' '160036' '24.9']
     [" 'FUELINSTHHCUR'" "'PS'" '  297' ' 1. ' '  412' ' 1.4' '  8136' ' 1.3']
     [" 'FUELINSTHHCUR'" "'NPSHYD'" '  322' ' 1.1' '  319' ' 1.1' '  8015'
      ' 1.2']
     [" 'FUELINSTHHCUR'" "'OTHER'" '  129' ' 0.4' '  128' ' 0.4' '  3093'
      ' 0.5']
     [" 'FUELINSTHHCUR'" "'INTFR'" ' 1494' ' 5.1' ' 1494' ' 5.1' ' 31731'
      ' 4.9']
     [" 'FUELINSTHHCUR'" "'INTIRL'" '    0' ' 0. ' '    0' ' 0. ' '  2650'
      ' 0.4']
     [" 'FUELINSTHHCUR'" "'INTNED'" '  882' ' 3. ' '  880' ' 3. ' ' 18991'
      ' 2.9']
     [" 'FUELINSTHHCUR'" "'INTEW'" '    0' ' 0. ' '    0' ' 0. ' '     0'
      ' 0. ']
     [" 'FUELINSTHHCUR'" "'BIOMASS'" ' 1608' ' 5.5' ' 1630' ' 5.6' ' 37688'
      ' 5.9']]
     --data--
    [["'CCGT'" '10430']
     ["'OCGT'" '    0']
     ["'OIL'" '    0']
     ["'COAL'" '    0']
     ["'NUCLEAR'" ' 6963']
     ["'WIND'" ' 6986']
     ["'PS'" '  297']
     ["'NPSHYD'" '  322']
     ["'OTHER'" '  129']
     ["'INTFR'" ' 1494']
     ["'INTIRL'" '    0']
     ["'INTNED'" '  882']
     ["'INTEW'" '    0']
     ["'BIOMASS'" ' 1608']]

在python中拔出2d数组的2,3列

2 个答案: