如何从python中的文本文件创建一个类？

Question

How would i create a class from a Text_file.txt containing the below data. So that AI are my objects.

Text_file.txt format:

[{'A': 443582874, 'B': '015490199481', 'C': 98874007784, 'D': 'Banana', 'E': 'buy', 'F': '0.2000', 'G': '0.031076', 'H': '-0.000000621520', 'I': '2019-02-01T11:19:22.740Z'}, {'A': 443484705, 'B': '015490131470', 'C': 98848326070, 'D': 'Apple', 'E': 'sell', 'F': '0.2000', 'G': '0.030879', 'H': '-0.000000617580', 'I': '2019-02-01T09:35:09.198Z'}]

So that when:

print(class['D0']):

Returns:

Banana

And

print(class['D0':'D1'])

Returns:

Banana
Apples

Answer 1

This is not really a thing, but there is a way of doing it.

If instead of it being text_file.txt the file was text_file.py and the contents were something like this:

var = [{'A': 443582874, 'B': '015490199481', 'C': 98874007784, 'D': 'Banana', 'E': 'buy', 'F': '0.2000', 'G': '0.031076', 'H': '-0.000000621520', 'I': '2019-02-01T11:19:22.740Z'}, {'A': 443484705, 'B': '015490131470', 'C': 98848326070, 'D': 'Apple', 'E': 'sell', 'F': '0.2000', 'G': '0.030879', 'H': '-0.000000617580', 'I': '2019-02-01T09:35:09.198Z'}]

then in your script you had

from text_file import var

print(var[0]['D'])

that would give you 'Banana' .

You would need text_file.py to be in the same folder (or at least somewhere in your path) as your python script, so that it could be imported.

I do this sometimes for configs. You are also mis-using the name class which isn't what this is.

---

Edit:

doing this:

print(class['D0':'D1'])

is probably possible, but I don't think it's what you want at all - to do it you would basically be rebuilding your own indexing symantics for a different data structure - why not just learn the one that python already has?

something like this:

print([i['D'] for i in var[0:1]])

would give you what you want

Answer 2

class is a Python reserved word with a special meaning, which I don't think is what you mean here.

What you appear to have is a JSON string, which can be imported into Python as a 2-element list of dicts. Except it's using single-quotes instead of double-quotes. So read the file into string , then

import json

string = string.replace( "'", '"')
j = json.loads( string)

you can now refer to j[0]['D'] and [ x['D'] for x in j ] (the latter is the list ['Banana', 'Apple']