I have a text file which contains a matrix of numbers:
999 999 10 8
3 4 999 999 999
6 999 2 7 999
999 6 3 5 6
999 9 1 10 999
10 6 999 2 2 999
I'm trying to read each line and store it into an array in Python but
I'm having trouble changing each value into an int from a string. I tried using the int() when parsing each line but I get the error of not being able to pass list into the int() argument.
try that:
matrix = [[int(i) for i in line.split()] for line in open('myfile.txt')]
[edit] if you don't want the first line just read it before.
with open('myfile') as f:
f.readline()
matrix = ....
Using map() to get a list of lists:
>>> with open('myfile.txt') as matrix:
... [map(int, line.split()) for line in matrix]
...
[[999, 999, 10, 8], [3, 4, 999, 999, 999], [6, 999, 2, 7, 999], [999, 6, 3, 5, 6], [999, 9, 1, 10, 999], [10, 6, 999, 2, 2, 999]]
map inside a list comprehension if map does the same thing as [f(x) for x in iterable]?map() eliminates the inner for loop you are using inside your answerFor each line, split on space character, and then convert each token to an int. One way to do this, using list comprehension, is:
s = "999 999 10 8"
[int(t) for t in s.split(" ")]
#evaluates to [999, 999, 10, 8]
nums = []
with open('file.txt') as f:
for line in f:
nums.append([int(n) for n in line.split()])
You could write that as one list comprehension, but that could get nasty.
