Question

I would like to write a 2-D array to a Python 3 txt file.

e.g.

 My_list = ['Hello', 'World', 0], ['Pretty', 'World', 1], ['Tired', 'World', 2]]

going into my_text.txt.

I have tried loads of approaches none of which I can recommend as I get a variety of results including 1 element Lists:

["['Hello', 'World', 0], ['Pretty', 'World', 1], ['Tired', 'World', 2]"]

and lists of strings:

["[Hello', 'World', 0]", "['Pretty', 'World', 1]", "['Tired', 'World', 2]"]

along with other wonderful results. Does anyone know some of some simple straightforward code for this or a tutorial? Just doing this out of curiosity, tbh and am struggling badly.

I would like to be able to read my List out from the file again and use it fully as a List once again e.g, print(my_list[0][0]) yields 'Hello'

Answer 1

json is good at serializing lists/dicts/numbers/strings:

import json 

My_list = [['Hello', 'World', 0], ['Pretty', 'World', 1], ['Tired', 'World', 2]]

#write to file
with open("data.json", "w") as file:
    json.dump(My_list, file)

#read from file
with open("data.json") as file:
    new_list = json.load(file)

print(new_list)

Result:

[['Hello', 'World', 0], ['Pretty', 'World', 1], ['Tired', 'World', 2]]

Answer 2

还要考虑 yaml 。需要安装 pyyaml （push()）。

pip install pyyaml

将列表对象保存到文件：

import yaml

输出文件如下：

my_list = [['Hello', 'World', 0], ['Pretty', 'World', 1], ['Tired', 'World', 2]]

with open('my_list.yml', 'w') as outfile:
    yaml.dump(my_list, outfile, default_flow_style=False)

要重新加载列表：

- - Hello
  - World
  - 0
- - Pretty
  - World
  - 1
- - Tired
  - World
  - 2

要直接处理字符串，可以使用标准库ast.literal_eval，这是一个简单的示例，您可以进一步自定义。

with open("my_list.yml", 'r') as inputfile:
    my_list_back = yaml.load(inputfile)

比基本的读/写操作可能是：

import ast

string_list = (str(my_list)) # convert tostring then save it to file
print(string_list.__class__) # it's a string
reconverted_list = ast.literal_eval(string_list) # convert back with ast
print(reconverted_list.__class__) # it's a list

Answer 3

嗨，有兴趣的人。

我想将数组保存到Python文本文件中并完全检索它，以便可以处理所有元素。

我确定要解决我的问题，并用非常混乱的代码解决了这个问题。

下面的代码完成了我想做的事情。

没有意义的运动，但我只需要做。

感谢您的帮助和想法。

my_list = []
my_list_669 = []

def create_list():
    #Creating the list

    for x in range(5):
        my_list.append(["Hello", "World", x])

    print("my_list = ", my_list)


def save_list_to_file():
    #creating the string

    string_1 = ""

    for item in my_list:
        string = item[0] + "," + item[1] + "," + str(item[2]) + "\n"
        string_1 += string
        #adds records to a string with a line return after each record

    with open('your_file.txt', 'w') as f:
            f.write(string_1)


def recover_list():

    with open('your_file.txt', 'r') as f:
            tiing = f.read().splitlines()
            #splits lines at \n and inserts into array called 'tiing'
            #each item is equivalent to a record

    for items1 in tiing:
        my_list_69 = items1.split(",")
        #splits the array items in ting at "," mark
        #these are now in an array called 'my_list_69'
        #below I access all items from within the list
        #and append them to a temporary sub-list

        sub_list = []
        for items in my_list_69:
            sub_list.append(items)

        my_list_669.append(sub_list)  this reconstructs the list


create_list()
save_list_to_file()
recover_list()

Testing:
print(my_list_669)
print(my_list_669[0])
print(my_list_669[0][2])
for items in my_list_669:
    print(items)

Writing a 2-D List to a File, Reading it out and Re-Using saved List

3 个答案: