Array string format to real array

Question

I have this string

'[334.0, 223.0, 41.0, 819.0]'

And I need to transform this in this array:

[334.0, 223.0, 41.0, 819.0]

Any ideas? Thanks

score 3 · Accepted Answer · answered May 25 '18 at 10:44

3

Use the ast module.

Ex:

import ast
print(ast.literal_eval('[334.0, 223.0, 41.0, 819.0]'))

output:

[334.0, 223.0, 41.0, 819.0]

answered May 25 '18 at 10:44

Rakesh

Really nice dude, can you explain to me how it works? – Miguel Santos May 25 '18 at 10:45
1

https://docs.python.org/3/library/ast.html#ast.literal_eval – Rakesh May 25 '18 at 10:46
much love to you man – Miguel Santos May 25 '18 at 10:48
You are welcome :) – Rakesh May 25 '18 at 10:51
I cant, I have to wait 15mins (1 left) but I will – Miguel Santos May 25 '18 at 10:58

score 1 · Answer 2 · answered May 25 '18 at 10:47

1

Simple one-liner with no extra imports:

a = '[334.0, 223.0, 41.0, 819.0]'

b = [ float(i) for i in a[1:-1].split(',') ]

print b

Output:

[334.0, 223.0, 41.0, 819.0]

answered May 25 '18 at 10:47

amitchone

`float(223)` will produce the output `223.0`. (It seems that the commenter deleted the comment. This was in response to: What if we have an integer value in `a`). – amitchone May 25 '18 at 10:54

Riccardo Petraglia · Answer 3 · 2018-05-25T10:48:54.293

-1

What about eval?

That would evaluate a string as if it is a python code.

For example:

string='[334.0, 223.0, 41.0, 819.0]'
a = eval(string)
print(a[0])

output:

334.0

edited May 25 '18 at 10:48

answered May 25 '18 at 10:45

4

[Eval is evil](https://stackoverflow.com/questions/1832940/why-is-using-eval-a-bad-practice?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa) – awesoon May 25 '18 at 10:46
@soon Only if you do not know what you are doing. ;) – Riccardo Petraglia May 25 '18 at 10:50
2

Let's be honest - most of developers do not know what are they doing. `ast.literal_eval` behaves like `eval` for objects and it is safe – awesoon May 25 '18 at 10:54

3 Answers3