完全按照变量中的定义输出字典到文件

Question

I am wondering if there is a way to output a dictionary to a file exactly as it would be defined as a variable?

So if in code it looks like:

dict1 = {01: 'val1', 02: 'val2', 03: 'val3'}

the contents of the file would look identical?

So file contains:

dict1 = {01: 'val1', 02: 'val2', 03: 'val3'}

I've heard of pickle and JSON but I ideally want to be able to import them from a module, ie

from some_module import some_dict

Is this possible?

Answer 1

Simply use the built-in repr(...) function that converts objects to a string in that way that the resulting string is a valid literal with which you could recreate the object.

It calls its argument's __repr__() method which at least produces valid literals for the most common basic data types. It does not work for most other objects though:

dict1 = {1: 'val1', 2: 'val2', 3: 'val3'}
literal = repr(dict1)

print(literal)
# Output: {1: 'val1', 2: 'val2', 3: 'val3'}

Now you could store that in a Python file:

with open("my_dict.py", "w") as f:
    print("dict2 = " + literal, file=f)

And this is now importable as module from other Python scripts inside the same folder:

import my_dict
print(my_dict.dict2[2])
# Output: val2

Or if you don't want to use the module name each time, import it using from :

from my_dict import dict2
print(dict2[2])
# Output: val2

Answer 2

I don't think that is possible. Imports are used for importing modules, not files. You will need to read and process the file in order for this to work. You can write the dict to a file with for example:

output = "dict1 = "+str(dict1) 
f.write(output)

Answer 3

You can achieve an objects name by using the globals() function which shows you a dictionary over the current state of the module. But this is not a good scenario, you should use serialization of your data, maybe by JSON.