I found an interesting problem on https://www.codewars.com/kata/59f04228e63f8ceb92000038:
The number ```1331``` is the first positive perfect cube,  higher than ```1```, having all its digits odd (its cubic root is ```11```).

The next one is ```3375```.

In the interval [-5000, 5000] there are six pure odd digit perfect cubic numbers and are: ```[-3375,-1331, -1, 1, 1331, 3375]```

Give the numbers of this sequence that are in the range ```[a,b] ```(both values inclusive)

Examples:
``` python
odd_dig_cubic(-5000, 5000) == [-3375,-1331, -1, 1, 1331, 3375] # the output should be sorted.
odd_dig_cubic(0, 5000) == [1, 1331, 3375]
odd_dig_cubic(-1, 5000) == [-1, 1, 1331, 3375]
odd_dig_cubic(-5000, -2) == [-3375,-1331]

```
Features of the random tests for python:
```
number of Tests = 94
minimum value for a = -1e17
maximum value for b = 1e17
```
You do not have to check the entries, ```a``` and ```b``` always integers and ```a < b``` 

Working well in Python 2 and Python 3.
Translation into Ruby is coming soon.

I tried it in Python, but could not do it. Can you solve it?
def get_podpc():
    r=[]
    x=1
    while (x*x*x<=1e17):
        y=x*x*x
        if all(int(d)%2==1 for d in str(y)):
            r.append(y)
        x+=2
    return sorted([-1*x for x in r]+r)

arr=get_podpc()

def odd_dig_cubic(a, b):
    return [x for x in arr if a<=x<=b]