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Array of Python load from ascii .txt file.

There is a .txt file named "array.txt" which contains the following 5x5 array of two-digit numbers:

+-------------------------+

¦ 34 ¦ 21 ¦ 32 ¦ 41 ¦ 25  ¦

+----+----+----+----+-----¦

¦ 14 ¦ 42 ¦ 43 ¦ 14 ¦ 31  ¦

+----+----+----+----+-----¦

¦ 54 ¦ 45 ¦ 52 ¦ 42 ¦ 23  ¦

+----+----+----+----+-----¦

¦ 33 ¦ 15 ¦ 51 ¦ 31 ¦ 35  ¦

+----+----+----+----+-----¦

¦ 21 ¦ 52 ¦ 33 ¦ 13 ¦ 23  ¦

+-------------------------+

I want a script that reads this file automatically without manually specifying:

array = np.matrix([[34,21,32,41,25],[14,42,43,14,31],[54,45,52,42,23],[33,15,51,31,35],[21,52,33,13,23]])

All I have is this:

import numpy as np
np.loadtxt('array.txt', skiprows=1)

which returns the error "ValueError: cannot convert string to float: b'xa6". So it seems like he doesn't like ascii characters. Is there a function that can only read the numeric values ​​of a text file into an array? Thanks so much for reading, any help would be infinitely appreciated.

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3 answers


You can use regex to extract numbers from strings:



import re, numpy
with open(myFile, 'r') as content:
    # This extracts all word boundary-delimited numbers from each line
    x = [re.findall(r'\b\d+\b', i) for i in content.readlines()]
# Then you keep only those lines that contained a number and 
#  convert the resulting list to an array
myArray = numpy.array([i for i in x if len(i) > 0])
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Here's how to do it in one line or two:



import re

import numpy as np


numbers = re.compile(r'\d+')

np.array([map(int, numbers.findall(line)) 
          for line in open("array.txt", "r") 
          if numbers.search(line) is not None])
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Assuming these are the only delimiters you'll ever run into your .txt file, here's a little I know in Python 2.7.

array = []
for line in open('array.txt', 'r').readlines():
    if line.startswith('\xc2'):
        line = line.replace('\xa6','').replace('\xc2',',').split(',')
        line[:] = [int(x) for x in line if x not in ['','\n']]
        array.append(line)

Calling additional print array

in the test text file you gave gives this output:

[[34, 21, 32, 41, 25], [14, 42, 43, 14, 31], [54, 45, 52, 42, 23], [33,  15, 51, 31, 35], [21, 52, 33, 13, 23]]

Here you can customize it to suit your numpy needs.

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