How to import a string file into a list of lists?

Question

I basically have a text file:

-1 2 0 0 0 0 0 2 -1 -1 -2 0 0 -2 2 0 1 0 

Who do I want to put on the list of lists so that it looks like this:

 [[-1,2,0],[0,0,0],[0,2,-1],[-1,-2,0],[0,-2,2],[0,1,0]] 

I have this code so far, but it creates a list of strings in lists.

 import os f = open(os.path.expanduser("~/Desktop/example board.txt")) for line in f: for i in line: line = line.strip() line = line.replace(' ',',') line = line.replace(',,',',') print(i) print(line) b.append([line]) 

This creates [['-1,2,0'],['0,0,0'],['0,2,-1'],['-1,-2,0'],['0,-2,2'],['0,1,0']] This is almost what I want, except for quotation marks.

Answer 1

A simple solution without additional libraries

 import os lines = [] f = open(os.path.expanduser("~/Desktop/example board.txt")) for line in f: x = [int(s) for s in line.split()] lines.append(x) 

Output:

 [[-1, 2, 0], [0, 0, 0], [0, 2, -1], [-1, -2, 0], [0, -2, 2], [0, 1, 0]] 

Answer 2

I would recommend just using numpy for this, rather than reinventing the wheel ...

 >>> import numpy as np >>> np.loadtxt('example board.txt', dtype=int).tolist() [[-1, 2, 0], [0, 0, 0], [0, 2, -1], [-1, -2, 0], [0, -2, 2], [0, 1, 0]] 

Note. Depending on your needs, you may find a numpy array that will become a more useful data structure than a list of lists.

Answer 3

Use the csv module:

 import csv with open(r'example board.txt') as f: reader = csv.reader(f, delimiter='\t') lines = list(reader) print lines 

Answer 4

This should do the trick, as it seems like you want the data to be numbers, not strings:

 fin = open('example.txt','r') # The list we want list_list = [] for line in fin: # Split the numbers that are separated by a space. Remove the CR+LF. numbers = line.replace("\n","").split(" ") # The first list list1 = [] for digit in numbers: list1.append(int(digit)) # The list within the list list_list.append(list1) fin.close() 

This creates the following conclusion:

 [[-1, 2, 0], [0, 0, 0], [0, 2, -1], [-1, -2, 0], [0, -2, 2], [0, 1, 0]] 

Answer 5

If you have comma separated values, csv is often the best choice. If this does not work, for some reason, then you can do only with lines and lists of built-in modules.

You can do all this in a list comprehension:

 with open('~/Desktop/example board.txt', 'r') as fin: lines = [[int(column.strip()) for column in row.split(',')] for row in fin] 

But it is opaque and can be remodeled:

 def split_fields(row): fields = row.split(',') return [int(field.strip()) for field in fields] with open('~/Desktop/example board.txt', 'r') as fin: lines = [split_fields(row) for row in fin]