Question

我在.txt文件中读取了以下字符串

{{1,2,3,0}，{4,5,6,7}，{8，-1,9,0}}

使用lin = lin.strip()删除'\ n'

然后我将{和}替换为[和]使用

lin = lin.replace ("{", "[")

lin = lin.replace ("}", "]")

我的目标是将lin转换为float 2d数组。所以我做了

my_matrix = np.array(lin, dtype=float)

但是我收到一条错误消息：“ValueError：无法将字符串转换为float：[[1,2,3,0]，[1,1,1,2]，[0，-1,3,9 ]]“

删除dtype，我得到一个字符串数组。我已经尝试将lin乘以1.0，使用.astype（float）复制lin，但似乎没有任何效果。

Answer 1

我使用JSON库来解析文件的内容，然后遍历数组并将每个元素转换为float。但是，整数解决方案可能已足以满足您的需求。那个更快更短。</ p>

import json

fc = '{{1,2,3,0},{4,5,6,7},{8,-1,9,0}}'

a = json.loads(fc.replace('{','[').replace('}',']'))

print(a) # a is now array of integers. this might be enough

for linenumber, linecontent in enumerate(a):
    for elementnumber, element in enumerate(linecontent):
        a[linenumber][elementnumber] = float(element)

print(a) # a is now array of floats

更短的解决方案

import json

fc = '{{1,2,3,0},{4,5,6,7},{8,-1,9,0}}'

a = json.loads(fc.replace('{','[').replace('}',']'))

print(a) # a is now array of integers. this might be enough

a = [[float(c) for c in b] for b in a]

print(a) # a is now array of floats

（适用于python 2和3）

Answer 2

import numpy as np

readStr = "{{1,2,3,0},{4,5,6,7},{8,-1,9,0}}"
readStr = readStr[2:-2]
# Originally read string is now -> "1,2,3,0},{4,5,6,7},{8,-1,9,0"

line = readStr.split("},{")
# line is now a list object -> ["1,2,3,0", "4,5,6,7", "8,-1,9,0"]

array = []
temp = []
# Now we iterate through 'line', convert each element into a list, and
#     then append said list to 'array' on each iteration of 'line'
for string in line:
    num_array = string.split(',')
    for num in num_array:
        temp.append(num)
    array.append(temp)
    temp = []

# Now with 'array' -> [[1,2,3,0], [4,5,6,7], [8,-1,9,0]]
my_matrix = np.array(array, dtype = float)

# my_matrix = [[1.0, 2.0, 3.0, 0.0]
#              [4.0, 5.0, 6.0, 7.0] 
#              [8.0, -1.0, 9.0, 0.0]]

虽然这可能不是最优雅的解决方案，但我认为它很容易理解，并为您提供您正在寻找的内容。

Python 2.7将2d字符串数组转换为float数组

2 个答案: