如何从给定的txt文件创建字典？

Question

I have a text file consisting of usernames and a passwords, separated by a comma that I need to convert into a dictionary like this:

userData = [{'username': 'something@test.com', 'password': 'test123'},
            {'username': 'somethingelse@test.com', 'password': 'test1234'},
            {'username': 'somethingmore@test.com', 'password': 'test123'},
            ]

The file looks like this:

something@test.com,test123
somethingelse@test.com,test1234
somethingmore@test.com,test123

I tried the following, but it only returns the last line of the text file, so I assume the dictionary is overwritten for each line.

file = open('username.txt', 'r')
userData = {}
userData['username'] = ''
userData['password'] = ''

for line in file:
   x = line.split(',')
   un = x[0]
   pw = x[1]
   userData['username']=un
   userData['password']=pw

What can I do to get the correct output?

Answer 1

You want a list of dictionaries, but you only create a dictionary that it's modified each time in for loop. You have to create another dictionary for each line and store it in list.
Try this:

file = open('username.txt', 'r')
userDataList = []

for line in file:
   x = line.split(',')
   userData = {}
   userData['username'] = x[0]
   userData['password'] = x[1]
   userDataList.append(userData)

Answer 2

This should work:

file = open('username.txt', 'r')
userData = {}

for line in file:
   x = line.split(',')
   userData[x[0]] = x[1]

In your original code you're not actually altering the dictionary, just one username and password.

EDIT: I misread the question. Mine stores each username as a key and each password as the value.

Answer 3

Use DictReader in the csv module:

import csv

with open('usernames.txt') as csvfile:
    reader = csv.DictReader(csvfile,
                            fieldnames=['username', 'password'])
    users = list(reader)

For example:

>>> import csv
>>> import pprint
>>> from StringIO import StringIO

>>> content = """something@test.com,test123
... somethingelse@test.com,test1234
... somethingmore@test.com,test123"""

>>> usernames = StringIO(content)
>>> pprint(list(csv.DictReader(usernames,
...                            fieldnames=['username', 'password'])))
[OrderedDict([('username', 'something@test.com'), ('password', 'test123')]),
 OrderedDict([('username', 'somethingelse@test.com'),
              ('password', 'test1234')]),
 OrderedDict([('username', 'somethingmore@test.com'), ('password', 'test123')])]

Answer 4

It looks like what you actually want to do is create a list of dictionary objects. I'd use the csv module to read the data, since the content of the file appears to be that of Character Separated Values.

import csv
import sys

def open_csv(filename, mode='r'):
    """Open a csv file in proper mode depending on Python verion."""
    return(open(filename, mode=mode+'b') if sys.version_info[0] == 2 else
           open(filename, mode=mode, newline=''))

def read_data(filename, fieldnames):
    with open_csv(filename, mode='r') as file:
        for row in csv.DictReader(file, fieldnames=fieldnames):
            yield row

fieldnames = 'username password'.split()
user_data = [row for row in read_data('username.txt', fieldnames)]

print(user_data)

Output:

[{'username': 'something@test.com', 'password': 'test123'}, {'username': 'somethingelse@test.com', 'password': 'test1234'}, {'username': 'somethingmore@test.com', 'password': 'test123'}]