If I have a text file containing the following numbers:
5.078780 5.078993
7.633073 7.633180
2.919274 2.919369
3.410284 3.410314
How can read it and store it in an array, so that it becomes:
[[5.078780,5.078993],[7.633073,7.633180],[2.919274,2.919369],[3.410284,3.410314]]
with open('test.txt', 'r') as file:
output = [ line.strip().split(' ') for line in file.readlines()]
# Cast strings to floats
output = [[float(j) for j in i] for i in output]
print(output)
should give the desired output:
[[5.07878, 5.078993], [7.633073, 7.63318], [2.919274, 2.919369], [3.410284, 3.410314]]
Approach:
Have a result list = []
Split the text by newlines \n.
Now in a for-loop
split each line by a space char and assign to a tuple
append tuple to the result list
I'm refraining from writing code here to let you work it out.
This should do
with open ("data.txt", "r") as myfile:
data=myfile.readlines()
for i in range(len(data)):
data[i]=data[i].split()
Python provides the perfect module for this, it's called csv:
import csv
def csv_to_array(file_name, **kwargs):
with open(file_name) as csvfile:
reader = csv.reader(csvfile, **kwargs)
return [list(map(float, row)) for row in reader]
print(csv_to_array('test.csv'))
If you later have a file with a different field separator, say ";", then you'll just have to change the call to:
print(csv_to_array('test.csv', delimiter=';'))
Note that if you don't care about importing numpy then this solution is even better.
You first want to retrieve the file content in an array of string (each string is one line of the file)
with open("myfile.txt", 'r') as f: file_content = f.readlines()
Refer to open doc for more: https://docs.python.org/3/library/functions.html#open
Then you want to create a list
content_list = []
And then you want to fill it with each string, when each string should be split with a space(using split() function) which make a list with the two values and add it to content_list, use a for loop !
for line in file_content:
values = line.split(' ') # split the line at the space
content_list.append(values)
By the way, this can be simplified with a List Comprehension:
content_list = [s.split(' ') for s in file_content]
To convert to this exact format :
with open('filepath', 'r') as f:
raw = f.read()
arr = [[float(j) for j in i.split(' ')] for i in raw.splitlines()]
print arr
outputs :
[[5.07878, 5.078993], [7.633073, 7.63318], [2.919274, 2.919369], [3.410284, 3.410314]]
with open('blah.txt', 'r') as file:
a=[[l.split(' ')[0], l.split(' ')[1] for l in file.readlines() ]
