I have an array a and I would like to repeat the elements of a n times if they are even or if they are positive. I mean I want to repeat only the elements that respect some condition.
If a=[1,2,3,4,5] and n=2 and the condition is even, then I want a to be a=[1,2,2,3,4,4,5].
a numpy solution. Use np.clip and np.repeat
n = 2
a = np.asarray([1,2,3,4,5])
cond = (a % 2) == 0 #condition is True on even numbers
m = np.repeat(a, np.clip(cond * n, a_min=1, a_max=None))
In [124]: m
Out[124]: array([1, 2, 2, 3, 4, 4, 5])
Or you may use numpy ndarray.clip instead of np.clip for shorter command
m = np.repeat(a, (cond * n).clip(min=1))
Using itertools,
a = [1,2,3,4,5]
n = 2
# this can be any condition. E.g., even only
cond = lambda x: x % 2 == 0
b = list(itertools.chain.from_iterable( \
(itertools.repeat(x, n) if cond(x) else itertools.repeat(x,1)) \
for x in a))
b
# [1, 1, 2, 2, 3, 3, 4, 4, 5, 5]
(The awkward repeat(x,1) is to allow use of chain and avoid having to flatten an array of mixed integers and generators...)
Below would do what you are looking for -
import numpy as np
a = np.asarray([1,2,3,4,5])
n = int(input("Enter value of n "))
new_array = []
for i in range(0,len(a)):
counter = np.count_nonzero(a == a[i])
if a[i]%2 != 0:
new_array.append(a[i])
elif a[i]>0 and a[i]%2 == 0:
for j in np.arange(1,n+1):
new_array.append(a[i])
Try a simple for-loop:
>>> a = [1,2,3,4,5]
>>> new_a = []
>>> n = 2
>>>
>>> for num in a:
... new_a.append(num)
... if num % 2 == 0:
... for i in range(n-1):
... new_a.append(num)
...
>>> new_a
[1, 2, 2, 3, 4, 4, 5]
