Given the sample below:
from itertools import permutations
p=permutations("abc", 2)
def func():
for i in p:
print("values=", i)
print("First use case:")
func()
print("Second use case:")
func()
print("The End!")
Output:
First use case:
values= ('a', 'b')
values= ('a', 'c')
values= ('b', 'a')
values= ('b', 'c')
values= ('c', 'a')
values= ('c', 'b')
Second use case:
The End!
The question is about the second function CALL, why doesn't print the values?!
p is and iterator which means once you finish iterating through it there are no more elements in it. You will have to regenerate the iterator.
Like:
def func():
p=permutations("abc", 2)
for i in p:
print("values=", i)
If you have situation where the iterator is generated randomly and you want to use the same random elements then you will have to move them to something like a list.
Example:
from numpy.random import permutation
import numpy as np
p = list(iter(np.random.randint(0,10,10)))
def func():
for i in p:
print("values=", i)