CODEWITHSUNDEEP
pythoncsvpython-3.x
Panda God
Panda God

Reputation: 11

Recognizing a list from a text file

I have a text file, "blah.txt" and within it contains this data:

blah1: [01,02,03]

blah2: [01,02,03]

I can read through the file and put it into a list with this:

reader = csv.reader(open('blah.txt'),delimiter=":")

But [01,02,03] isn't recognized as a list, but as a string. Is there a short and simple way to make it so that it does recognize it as a list?

Full code:

import csv, operator
reader = csv.reader(open('file.txt'),delimiter=":")
sortedlist = sorted(reader, reverse=True)
for name, score in sortedlist:
    print(score)

Edit:

I can instead write the data as

blah1:010203

blah2:010203

and use this:

import csv, operator
reader = csv.reader(open('file.txt'),delimiter=":")
sortedlist = sorted(reader, reverse=True)
for name, score in sortedlist:
    score = [int(score[i:i+2]) for i in range(0, len(score), 2)]
    print(name, score)

However it isn't convenient to read from the text file directly (by person).

Upvotes: 1

Views: 56

Answers (4)

Panda God
Panda God

Reputation: 11

This is what I ended up using, thanks @timgeb for the suggestion.

reader = csv.reader(open(file + '.txt'),delimiter=":")
data = {}
for name, score in reader:
    data[name] = sorted(ast.literal_eval(score), reverse=True)

Upvotes: 0

Boa
Boa

Reputation: 2677

The input (line.txt): 

blah1: [01,02,03]
blah2: [01,02,03]
blah3: [01,02,03]
blah4: [01,02,03]

Process the file:

from collections import OrderedDict  # if you want to maintain the order

data = OrderedDict()

for line in open("list.txt").readlines():
    k, v = line.split(':')
    # from list (in string form), remove whitespace, remove brackets
    # turn the list (in string form) into a list
    data[k] = v.strip()[1:-1].split(',')

The result:

>>> data
OrderedDict([('blah1', ['01', '02', '03']), ('blah2', ['01', '02', '03']), 
('blah3', ['01', '02', '03']), ('blah4', ['01', '02', '03'])])

Upvotes: 0

timgeb
timgeb

Reputation: 78750

At first I thought ast.literal_eval was the right tool for this, but look what happens:

>>> literal_eval('[01,020,03]')
[1, 16, 3]

Since you probably don't want integers starting with zero to be interpreted in base 8, I don't think there's a much prettier solution than to split by comma:

>>> s = '[01,020,03]'
>>> [int(x) for x in s[1:-1].split(',')]
[1, 20, 3]

If you have a chance to write your integers without leading zeros to your file, ast.literal_eval wins again.

Upvotes: 1

gr1zzly be4r
gr1zzly be4r

Reputation: 2162

Say you have "[01,02,03]" stored as a string variable s. You can then do:

score = [int(x) for x in s.strip('[').strip(']').split(',')]

as long as there are no spaces in between the brackets.

Upvotes: 0

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