使用换行符将字典写入文本文件

Question

I have a python dictionary {'A': '1', 'B': '2', 'C': '3'} . I want to write this dictionary into a file. This is how I did it;

test_dict = {'A': '1', 'B': '2', 'C': '3'}
f = open("dict.txt", "w")
f.write(str(test_dict))
f.close()

However, what I want the text file is to look like this;

{
'A': '1', 
'B': '2', 
'C': '3',
}

How do I add the newline when writing to the text file? I am using python 3.7

Answer 1

The str () method for a dict return it as a single line print, so if you want to format your output, iterate over the dict and write in the file the way you want.

test_dict = {'A': '1', 'B': '2', 'C': '3'}
f = open("dict.txt", "w")
f.write("{\n")
for k in test_dict.keys():
    f.write("'{}':'{}'\n".format(k, test_dict[k]))
f.write("}")
f.close()

Answer 2

This method uses F-string which results in more readable code. F-string is supported in python v3, not v2

f = open("dict.txt", "w")
f.write("{\n")
    for k in test_dict.keys():        
        f.write(F"'{k}': '{test_dict[k]}',\n")  # add comma at end of line
    f.write("}")
    f.close()