从每行具有多个数字的文本文件输入数据-Python

Question

Lets say I have a data file that has this inside it:

23 33 45
91 81 414
28 0 4 
7 9 14
8 9 17
1 1 3
38 19 84

How can I import it into a list so that each individual number it its own item?

Answer 1

You can use, numpy loadtxt to read the data file to a numpy array

  from numpy import loadtxt
  a,b,c = loadtxt("filename", usecols=(0,1,2), unpack=True)

Output

  a = array([23, 91, 28, 7, 8, 1, 38])

Answer 2

You could alternatively use the python builtin functions like open file, split and readlines

with open('file.txt') as f:
for line in f:
  a, b, c = map(int, line.split())

Another approach is

 file                = open(filename)
 file_data           = file.readlines()

But, the output will be a list of strings. That is the each element in the list will represent one line in the file. If you use the above code the output will look like

 file_data = ['23 33 45', '91 81 414', '28 0 4 ', '7 9 14', '8 9 17', '1 1 3', '38 19 84']

You might want them to convert to either float or int. you could do that using again numpy's fromstring module

  from numpy import fromstring
  data = [fromstring(i, dtype=float, sep=' ') for i in file_data ]

Notice that, I have used a list comprehension in the above code(which is faster than the conventional python for loop.)