I have following array:
scores=[2.619,3.3, 9.67, 0.1, 6.7,3.2]
And I wish to retrieve the elements which more than 5 by following code:
min_score_thresh=5
Result=scores[scores>min_score_thresh]
Hence this will result me result:
[9.67, 6.7]
Now i wish to get the positions of this two element which is my expected answer will be store in variable x:
x = [2,4]
Please share me ideas, thanks
Use numpy.where for a vectorised solution:
import numpy as np
scores = np.array([2.619,3.3, 9.67, 0.1, 6.7,3.2])
min_score_thresh = 5
res = np.where(scores>min_score_thresh)[0]
print(res)
[2 4]
scores = [2.619, 3.3, 9.67, 0.1, 6.7, 3.2]
min_score_thresh = 5
# score is 5 or higher
result = []
# position in 'scores' list
indx = []
for i, item in enumerate(scores):
if item > min_score_thresh:
result.append(item)
indx.append(i)
x = indx
print(result)
print(x)
Getting the indices (or values) via list comprehension is easy:
In [33]: [i for i,v in enumerate(scores) if v>5]
Out[33]: [2, 4]
We can get both, as a list of tuples with:
In [34]: [(i,v) for i,v in enumerate(scores) if v>5]
Out[34]: [(2, 9.67), (4, 6.7)]
Then we can use a zip* idiom to 'transpose' this list:
In [35]: list(zip(*_))
Out[35]: [(2, 4), (9.67, 6.7)]
Or wrapping that all in one expression with unpacking:
In [36]: v,x = tuple(zip(*((i,v) for i,v in enumerate(scores) if v>5)))
In [37]: v
Out[37]: (2, 4)
In [38]: x
Out[38]: (9.67, 6.7)
At a first glance getting several lists from a list comprehension is tricky, but this zip* transposition takes care of that.
Using numpy:
x = np.flatnonzero(np.greater(scores, min_score_thresh)).tolist()
NOTE: .tolist() is not necessary if you can live with numpy.ndarrays.
def find_scores(a_list, min):
filters = list(filter( lambda x: x[1]> min, [(i[0],i[1]) for i in enumerate(a_list) ]))
return [i[0] for i in filters]
simple oneliners
scores = [2.619, 3.3, 9.67, 0.1, 6.7, 3.2]
min_score_thresh = 5
result = [scr for scr in scores if scr > min_score_thresh]
index_ = [scores.index(x) for x in result]
Using Dictionary,
scores = [2.619,3.3, 9.67, 0.1, 6.7,3.2]
min_score_thresh = 5
index_dict = {}
for index, word in enumerate(scores):
if word > min_score_thresh :
index_dict.setdefault(word, index)
print(*index_dict.values())
gives
2 4
[Program finished]
