Convert strings to list Python

Question

list_val = '["apple", "blue", "green", "orange", "cherry", "white", "red", "violet"]'

print type(list_var)
str

print type(list_var[0])
'['

I read list_val values from a file and how to convert list_var to list ? so that list_var [0] should be 'apple'.

Why not configure list_val as list and for each value, just append the item to the list? — Avihoo Mamka
– Avihoo Mamka, Commented Oct 12, 2015 at 5:29
How did the file end up like that in the first place? Are you trying to remember some list contents between runs of the program? — Karl Knechtel
– Karl Knechtel, Commented Oct 12, 2015 at 5:35

John La Rooy · Accepted Answer · 2015-10-12 05:28:47Z

6

>>> list_val = '["apple", "blue", "green", "orange", "cherry", "white", "red", "violet"]'
>>> 
>>> from ast import literal_eval
>>> list_val = literal_eval(list_val)
>>> list_val[0]
'apple'

answered Oct 12, 2015 at 5:28

John La Rooy

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Burger King · Accepted Answer · 2015-10-12 05:31:25Z

4

I recommend you use json.

import json
list_val = '["apple", "blue", "green", "orange", "cherry", "white", "red", "violet"]'
a = json.loads(list_val)
print a
# [u'apple', u'blue', u'green', u'orange', u'cherry', u'white', u'red', u'violet']
print type(a)
# <type 'list'>
print a[0]
# 'apple'

edited Oct 12, 2015 at 5:31

answered Oct 12, 2015 at 5:31

Burger King

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1 Comment

John La Rooy Over a year ago

This certainly works for the example input. The best choice depends on matching the source encoding to the decoder. The origin may very well be JSON in this case.

kmad1729 · Accepted Answer · 2015-10-12 05:29:11Z

2

you can use eval function. Be careful what you pass to eval though, malicious things can happen!

list_var = eval(list_val)

answered Oct 12, 2015 at 5:29

kmad1729

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1 Comment

The6thSense Over a year ago

eval is evil please use literal_eval instead

Mayur Koshti · Accepted Answer · 2015-10-12 12:32:09Z

1

Another way is using regex:

>>> import re
>>> list_val = '["apple", "blue", "green", "orange", "cherry", "white", "red", "violet"]'
>>> result = re.findall(r'\"([^\"]+)\"', list_val)
>>> result[0]
'apple'

answered Oct 12, 2015 at 12:32

Mayur Koshti

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