Reading data separated by colon per line in Python

问题

I'm creating a program that has the user's name and their answers to a guess the number game in a database - like format on Python. I have created a text file where all of the users' data is, in the form name : guess. For instance,

Dave:23
Adam:12
Jack:13
Dave:25
Adam:34

Now, I am trying to re - read the file into Python as a tuple, so I decided to use the line of code below (The real answer is 17):

dict(line.split(':', 1) for line in open('guesses.txt'))

But this will just hand me back an empty line in the IDLE.
Why is this not working?
To make it more simple, I need a tuple that has the user's name and then their guesses.

My dictionary should look like this:

{'Dave': 23 25, 'Jack' : 13, 'Adam' : 13 34}

Thanks, Delbert.

回答1:

Use a defaultdict and store values in a list:

s="""Dave:23
Adam:12
Jack:13
Dave:25
Adam:34
"""

from collections import defaultdict
d = defaultdict(list)

for line in s.splitlines():
    name,val = line.split(":")
    d[name].append(int(val))

print(d)
defaultdict(<class 'list'>, {'Jack': [13], 'Adam': [12, 34], 'Dave': [23, 25]})

So for your file just do the same:

d = defaultdict(list)
with open('guesses.txt') as f:
    for line in f:
        name,val = line.split(":")
        d[name].append(int(val))

Your own code should return {'Jack': '13', 'Dave': '25', 'Adam': '34'} where the the values for Dave and Adam are overwritten in the last two lines hence the need to store values in a list and append.

You also cannot use tuples as you mentioned in your answer without creating new tuples each time you want to add a new value as tuples are immutable.

You can print(dict(d)) or use pprint if you don't want the defaultdict(<class 'list'>,)

from pprint import pprint as pp

pp(d)
{'Adam': ['12', '34'],
 'Dave': ['23', '25'],
 'Jack': ['13']}

回答2:

from collections import defaultdict

result = defaultdict(list)
with open("guesses.txt") as inf:
    for line in inf:
        name, score = line.split(":", 1)
        result[name].append(int(score))

which gets you

# result
{ "Dave": [23, 25], "Jack": [13], "Adam": [12, 34] }

来源：https://stackoverflow.com/questions/28385822/reading-data-separated-by-colon-per-line-in-python

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python

text-files