I need to convert array like this:
[[1527 1369 86 86]
[ 573 590 709 709]
[1417 1000 68 68]
[1361 1194 86 86]]
to like this:
[(726, 1219, 1281, 664),
(1208, 1440, 1283, 1365),
(1006, 1483, 1069, 1421),
(999, 1414, 1062, 1351),]
I tried using convert diretly to tuple but got this:
( array([1527, 1369, 86, 86], dtype=int32),
array([573, 590, 709, 709], dtype=int32),
array([1417, 1000, 68, 68], dtype=int32),
array([1361, 1194, 86, 86], dtype=int32))
(array([701, 899, 671, 671], dtype=int32),)
The array method tolist
is a easy and fast way of converting an array to a list. It handles multiple dimensions correctly:
In [92]: arr = np.arange(12).reshape(3,4)
In [93]: arr
Out[93]:
array([[ 0, 1, 2, 3],
[ 4, 5, 6, 7],
[ 8, 9, 10, 11]])
In [94]: arr.tolist()
Out[94]: [[0, 1, 2, 3], [4, 5, 6, 7], [8, 9, 10, 11]]
For most purposes such as list of lists is just as good as a list of tuples, or tuple of tuples. They differ only in mutability.
But if you must have a tuples, a list comprehension does the conversion nicely.
In [95]: [tuple(x) for x in arr.tolist()]
Out[95]: [(0, 1, 2, 3), (4, 5, 6, 7), (8, 9, 10, 11)]
An alternative [tuple(x) for x in arr]
is a bit slower, because it is iterating on the array rather than on a list. It also produces a different result - though you have to examine the type
of the tuple elements to see that.
I strongly recommend starting with the tolist
method, and doing any list to tuple conversions after.
What about using tuble and map function like this:
import numpy
numpy_arr = numpy.array(((1527, 1369, 86, 86),(573 , 590 , 709, 709)))
converted_list = tuple(map(tuple,numpy_arr)) # as list
converted_arr = map(tuple,numpy_arr) #as array
print(converted_arr)
Here is the following function assuming you do not want the final object to be a numpy object.
def fun(var):
a=[]
for i in var:
a.append(tuple(i))
return a
if you want in one line
def fun(var):
return [tuple(i) for i in var]
If you prefer list comprehensions to map():
a = numpy.random.uniform(0,1,size=(4,4))
a_tuple_list = [tuple(row) for row in a]
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