CODEWITHSUNDEEP
pythondata-processing
Anonymous User
Anonymous User

Reputation: 41

Transform string of coordinates stored in a tuple into list

I have a string of coordinates stored in a sequence of tuples such as '(522, 187) (522, 187) (522, 191) (523, 188) (522, 190) (being stored in a deque first and then converted to string).

  1. How is it possible to transform this entity into a list/deque of tuples? So that it would look like [(522, 187), (522, 187), (522, 191), (523, 188), (522, 190)]?

Simple splitting with split(',') doesn't work, as it then separates every coordinate due to ',' inside the tuple.

  1. Is there any more convenient way of storing a list/deque of tuples in a single cell of .csv file? I need to store all coordinates received from every trial in an individual cell. Making two columns with _x and _y coordinates sometimes results into unequal length of these arrays.

Upvotes: 2

Views: 1252

Answers (4)

GraphicalDot
GraphicalDot

Reputation: 2821

Here is the answer, use regex.

res = [tuple(e.replace(" ", "").split(",")) for e in  re.findall("[1-9]{3}, [1-9]{3}", string)]

This will be a list of tuples of strings. To convert them into ints

list(map(lambda x: (int(x[0]), int(x[1])), res))

Havent gone through the optimization of this code.

Upvotes: 1

Mateo Lara
Mateo Lara

Reputation: 917

This worked for me:

a = '(522, 187) (522, 187) (522, 191) (523, 188) (522, 190)'
res = list(eval(a.replace(', ',',').replace(' ',',')))

Output:

[(522, 187), (522, 187), (522, 191), (523, 188), (522, 190)]

Upvotes: 1

Riccardo Bucco
Riccardo Bucco

Reputation: 15364

You could do something like this:

from ast import literal_eval

tuples = '(522, 187) (522, 187) (522, 191) (523, 188) (522, 190)'

result = [literal_eval(f'({x})') for x in tuples.strip('()').split(') (')]

You can just memorize tuples = str(result) next time! You can retrieve it with result = literal_eval(tuples)

Upvotes: 1

AKX
AKX

Reputation: 168913

You can split the string with ) (, then massage the individual tuples:

>>> [tuple(int(v) for v in a.strip("()").split(", ")) for a in s.split(') (')]
[(522, 187), (522, 187), (522, 191), (523, 188), (522, 190)]

Secondly, there are many ways. One would be to just store all coordinates as a single string, with the implicit knowledge they are X/Y pairs: 522,187,522,187,522,191,...

Or you could store [(522, 187), (522, 187), (522, 191)] directly and use ast.literal_eval() to rehydrate it to a list-of-tuples.

Or, most preferably, you could use a data format that's not as stringly typed as CSV is, such as pickle files if you're working with Python alone, JSON if you need interchange, ...

Upvotes: 2

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