If I have a text file like this:
Hello World
How are you?
Bye World
How would I read it into a multidimensional array like this:
[["Hello", "World"],
["How", "are", "you?"],
["Bye" "World"]]
I have tried:
textFile = open("textFile.txt")
lines = textFile.readlines()
for line in lines:
line = lines.split(" ")
But it just returns:
["Hello World\n", "How are you?\n", "Bye World"]
How do I read the file into a multidimensional array?
Use a list comprehension and str.split:
with open("textFile.txt") as textFile:
lines = [line.split() for line in textFile]
Demo:
>>> with open("textFile.txt") as textFile:
lines = [line.split() for line in textFile]
...
>>> lines
[['Hello', 'World'], ['How', 'are', 'you?'], ['Bye', 'World']]
It is good practice to use the
withkeyword when dealing with file objects. This has the advantage that the file is properly closed after its suite finishes, even if an exception is raised on the way. It is also much shorter than writing equivalent try-finally blocks.
str.split() with no arguments takes care of all type of whitespace characters.You can use map with the unbound method str.split:
>>> map(str.split, open('testFile.txt'))
[['Hello', 'World'], ['How', 'are', 'you?'], ['Bye', 'World']]
In Python 3.x, you have to use list(map(str.split, ...)) to get a list because map in Python 3.x return an iterator instead of a list.
map(lambda line: line.split, open('testFile.txt')), when I do str.splite it says str not object.
lambda, because str.split is unbound method. 'a b c'.split() is like str.split('a b c').str.splite? Is it a typo? Or, did you overwrite str?Adding to the accepted answer:
with open("textFile.txt") as textFile:
lines = [line.strip().split() for line in textFile]
This will remove '\n' if it is appended to the end of each line.
Also don't forget to use strip to remove the \n:
myArray = []
textFile = open("textFile.txt")
lines = textFile.readlines()
for line in lines:
myArray.append(line.split(" "))
A good answer would be :
def read_text(path):
with open(path, 'r') as file:
line_array = file.read().splitlines()
cell_array = []
for line in line_array:
cell_array.append(line.split())
print(cell_array)
Which is optimized for readability.
But python syntax let's us use less code:
def read_text(path):
with open(path, 'r') as file:
line_array = file.read().splitlines()
cell_array = [line.split() for line in line_array]
print(cell_array)
And also python let's us do it only in one line!!
def read_text(path):
print([[item for item in line.split()] for line in open(path)])
lines = map(str.split, open('testFile.txt'))