Python - Format file to list

Question

I've read some questions on how to pass a file to a list, but this file it's a bit trickier as there are different data types in it, all of them represented as a string in that file.

I've managed to get a file that looks like this:

['verb', 0, 5, 7]['noun', 9, 3, 4]

How can I turn this into a list that looks like:

list = [['verb', 0, 5, 7], ['noun', 9, 3, 4]]

where 'verb' and 'noun' are strings and all numbers are integers.

Answer 1

If you mean that the file consists of groups enclosed in square brackets, all in one line, then probably the best idea is to replace all ][ sequences by ],[ sequences so that your data becomes valid JSON, then parse it using json.loads :

import json
with open('myfile', 'r') as f:
    line = f.readline().rstrip()
list_of_lists = json.loads("[" + line.replace('][', '],[').replace("'", '"') + "]")

Answer 2

You can try this:

data = open('file.txt').read().strip('\n')
import re
lists = re.findall("\[(.*?)\]", data)
final_list = [[int(i) if i.isdigit() else i[1:-1] for i in b.split(", ")] for b in lists]

Answer 3

You could use regex for this task. Below you can find a sketch of how to apply this technique here:

import re

s = "['verb', 0, 5, 7]['noun', 9, 3, 4]"

#create the regex expression
pattern = re.compile(r'\[(.*?)\]')

#store the data here
result = []

#get every item entry using the regex expression
for x in re.findall(pattern, s):
    z = x.split(",")
    #parse the data entries
    result.append([z[0].replace("'", ""), int(z[1]), int(z[2]), int(z[3])])

result

>>>[['verb', 0, 5, 7], ['noun', 9, 3, 4]]

Answer 4

I would open the file, then read it, store in a string and replace all "]" with "],". Then I'd eval (yeah I know it's evil but...) that string and would convert it to a list.

with open('your_file.txt', 'r') as raw_file:
    your_str = raw_file.read()
your_str = your_str.replace('][', '],[')
your_list = list(eval(your_str))

If you know that the content of the file will be JSON, you can use json.loads instead of eval . In the example you gave above, you should convert ' to " in order to being valid JSON.

Answer 5

Follow this steps:

• Identify who is storing data in this no format
• Call them
• Talk with this person about benefits to store data in an standard format. They are some available formats: csv, json, xml.
• Ask them about to receive data in this format.
• Deserialize data from file in one line library utility. Like `json.load('your_file.txt')